That's not a fair comparison. Final Cut Pro's price on macOS has been $299.99 since 2011, and Apple sells a "Pro Apps Bundle for Education" available to everyone that includes Final Cut Pro, Logic Pro, and other macOS apps for $199.99 (https://www.apple.com/us-edu/shop/product/BMGE2Z/A/pro-apps-...).
I'm sure a lot of users would appreciate a one-time payment option for Final Cut Pro or Logic Pro on the iPad, including teenagers who have some money saved up.
Especially consider the need to update your software for NLE is highly selective. H.264 and H.265 were used over the years for LongGOP, while ProRes and DNxHD/DNxHR were all supported a long time ago. There are no reasons to update unless you need latest blackmagic RAW or ProRes RAW, which are well beyond normal consumer realm. AV1 may be a new thing, but that's it.
There are no continuous vital features updates like being able to read newer camera RAW files for ACR. I find a one-time payment much more suitable for FCP.
With LPX and anything remotely in music production area the subscription just seems dumb. Omnisphere, Komplete, FL Studio, Cubase, Pro Tools, Ableton Live were all in the realm for decades, and while subscription did became a thing (especially for very expensive samples like Hollywood, Spitfire, etc.) features in a DAW are sufficient for a long life cycle in production, and mandating a subscription for "keeping latest" just seems odd.
I'm sure a lot of users would appreciate a one-time payment option for Final Cut Pro or Logic Pro on the iPad, including teenagers who have some money saved up.