I’ve wondered how likely you’d be to face legal repercussions for going rogue and fixing old leaky wells. The main non-legal issue would be expertise and equipment. I’m thinking of organizations like wren.co that could do this.
Minimum cost would be in the $80k-100k range. Double or triple that if you run into any issues. My most expensive abandonment was around $400k, which was for a simple, vertical 5000ft well.
Also, old infrastructure is really old. It's not things from 20 years ago. It's 50-100 years ago. The law requiring escrow or insurance (it has some holes) dates from the 70's.
Finally, it often isn't done properly. Either way, there are a ton of improperly plugged and abandoned wells and other leaky infrastructure that goes undetected.
The regulations you're describing have existed for a long time, but that's not enough to fix the full issue.
That said, if you can find the land owner most will be willing to give you permission and warn you about hazards to worry about. Figure out how to do it right and for free - with a good insurance that you won't harm their land and you will have more work where you can get permission than you lifetime will allow you to fix.
https://welldonefoundation.org/faq/
Seems like the old wells effectively get defaulted to state ownership once the last owner goes bust.