I don't have a solution for this problem. There has to be something in between a one-time $10 purchase and a $120 annual subscription, but Apple hasn't shown any interest in finding it.
I think it's too late now. Apple has taught an entire generation of users that mobile software is not worth paying real money for and effectively killed the ecosystem of apps they need to promote the iPad as a general purpose computing device.
It's more work for the developer but they did a great write up on how they built this capability: https://medium.com/@drewmccormack/a-cash-cow-is-on-the-agend...
Compare that to desktop programs like Adobe Creative Cloud, which costs more than $500 a year. Or console games, where the console costs about $300 (Switch Lite) and a single game costs almost $100.
(All priced CAD, rounded.)
On a similar note, I pay on average 5USD per (PC) game by tracking sales and would only consider paying more than 10USD for new games that I want to play really badly (e.g. DOOM Eternal). Console game pricing always seemed way too high to me, I'd spend what I saved on not building a PC in just a few AAA titles.
I've been busy the last two decades too. I've built websites, used CAD to design and machine dozens of physical objects, designed circuit boards, wrote and compiled software, made music, simulated chemical reactions, created and edited text documents, converted files from all sorts of formats to other formats, deployed databases with millions of rows, run two small businesses, and sent and received thousands of communications over myriad channels. All using free and open source software.
If there's something I want to do with a computer and I can't find a free solution that does it I write new code to accomplish my task (but honestly, this almost never happens these days).