As a vegetarian that actually doesn't like many vegetables (I don't like bell peppers, for example, which severely limits my options) and who was a huge carnivore before going veggie ( and with more than one hunter in the family): I see two groups of meat eaters.
Group A, who just like the taste and texture of meat. For them, a variety of substitutes that adequately matched would suffice. As of today, we have many fake meats that do a good job of matching the taste/texture of HEAVILY PROCESSED meats (e.g. turkey loaf), but not matching more straightforward meats. Likely vat-grown meat will be the only reasonably quick way to match both demands for the general population. Outside of that as more research is done into faux meats to match tastes and textures we will presumably get there, and as meat alternatives become more popular there is a feedback loop where research gets more widespread and has a better ROI, so maybe it's not so far off, but I personally wouldn't bet on it. Expense is a big deal to this group, as they basically want to be content (food-wise) with minimal effort, so meat alternatives that are familiar and not expensive is not a difficult transition, particularly if meat becomes more expensive. Making it low-effort to know what you are getting also helps. Currently meat alternatives are completely separate from meats in the store, and the delivery very different. (a box of burgers or a bag of crumble, for example, vs the pile of ground beef).
Group B, who are invested into the particulars of meat. These are the ones who will debate for hours the precise way to grill the perfect steak. Like with audiophiles who complain of qualities I can't hear, I have to assume they aren't delusional, but it doesn't really matter for the purpose of your question. This group is unlikely to be satisfied by vat-grown meat, outside of random luck. I don't see this group changing within their lifetimes, though they can be swayed to alter portion sizes. Honestly, the best way to REDUCE meat consumption is to avoid angering this group - they can take meat becoming a bit more expensive and more of a luxury without a fuss, but if it looks like meat were to be banned or too expensive they would react with all the furor you can expect from someone losing something they are passionate about. And their message would resonate with Group A, because Group A is just looking to be content like they currently are, so change represents risk, not benefit. This means the goals of REDUCING meat consumption and REMOVING meat consumption are at odds with one another.
If you have ethical motivations, none of the above is fast and vat-grown meat research has its own ethical questions, but I don't see a realistic fast alternative that doesn't involve mass suffering (to more than humans) due to uncontrolled events.
Making convincing lab-grown A5 wagyu will help a lot with both groups, I'm guessing, assuming it can be done for less than the real thing.
In fact, I'd probably start there, since it's probably the first type of meat that could be made cheaper than the real thing, and it's a total luxury good that most people never get to experience, so it's not really competing with the real thing in most peoples' minds. Similar to the Tesla business model, start with the high margin stuff and move down as you ramp up volume and start getting efficiencies of scale and more R&D.
Group A, who just like the taste and texture of meat. For them, a variety of substitutes that adequately matched would suffice. As of today, we have many fake meats that do a good job of matching the taste/texture of HEAVILY PROCESSED meats (e.g. turkey loaf), but not matching more straightforward meats. Likely vat-grown meat will be the only reasonably quick way to match both demands for the general population. Outside of that as more research is done into faux meats to match tastes and textures we will presumably get there, and as meat alternatives become more popular there is a feedback loop where research gets more widespread and has a better ROI, so maybe it's not so far off, but I personally wouldn't bet on it. Expense is a big deal to this group, as they basically want to be content (food-wise) with minimal effort, so meat alternatives that are familiar and not expensive is not a difficult transition, particularly if meat becomes more expensive. Making it low-effort to know what you are getting also helps. Currently meat alternatives are completely separate from meats in the store, and the delivery very different. (a box of burgers or a bag of crumble, for example, vs the pile of ground beef).
Group B, who are invested into the particulars of meat. These are the ones who will debate for hours the precise way to grill the perfect steak. Like with audiophiles who complain of qualities I can't hear, I have to assume they aren't delusional, but it doesn't really matter for the purpose of your question. This group is unlikely to be satisfied by vat-grown meat, outside of random luck. I don't see this group changing within their lifetimes, though they can be swayed to alter portion sizes. Honestly, the best way to REDUCE meat consumption is to avoid angering this group - they can take meat becoming a bit more expensive and more of a luxury without a fuss, but if it looks like meat were to be banned or too expensive they would react with all the furor you can expect from someone losing something they are passionate about. And their message would resonate with Group A, because Group A is just looking to be content like they currently are, so change represents risk, not benefit. This means the goals of REDUCING meat consumption and REMOVING meat consumption are at odds with one another.
If you have ethical motivations, none of the above is fast and vat-grown meat research has its own ethical questions, but I don't see a realistic fast alternative that doesn't involve mass suffering (to more than humans) due to uncontrolled events.