Why would that be the case. If anything, the last 20 years have reinforced the idea that if enemy combatants simply embed themselves in civilian populations, they are virtually impossible to target without mass collateral damage.
No no no no no no no, please no. Under no circumstances is that OK.
If the enemy is in a group of civilians, you use the police, arrest them, put them for a trial and send to prison.
If the enemy is in a group of civilians, and your immediate action is to bomb them along with the civilians, then you don’t value the lives of those civilians. At best you don’t care whether those civilians are alive or dead, and at worst you actually want those civilians dead. In the former case, you are doing a war crime, a crime against humanity, in the latter case you are doing a genocide and using the enemy as an excuse or justification.
In any case, there are plenty of ways to get around that. Unless the mass casualty is the point.
How many places in a densely populated city can you precisely drop a bomb with no risk to civilians? Yes, technology has improved, but my point is that better tech doesn't just automatically make war less awful.
I don't believe the people operating the weapons are different in ways that make civilian casualties obsolete. In WW2 it was a decision to bomb population centers, not an accident. That decision can be made today too.
Even 100% accurate precision weapons are only as good as the target information supplied to them. Bad Intel and misidentified targets are very real factors that can cause a precision weapon to strike something they shouldn't.
The bombing of Dresden killed 25K people in 3days, not months of war.
The bombing of Tokyo killed 100K people in 1 day.
Furthermore, those cities were not where the military was actually operating. Hamas is operating its offensive throughout Gaza.