here's my best attempt to get the key points (still long, but shorter than the article at least):
crunchyroll is getting rid of typesetting in their subs. they're going from the good, modern subbing standard (aegisub/ass) - which lets you position, motion-track, and color code text anywhere on the screen - to one worse than what they had 16 years ago (back when their renderer couldn't handle anything fancier than 9-position placement and overlapping text). the one they're moving to (ttml) doesn't let you do any special formatting, just plain text at the top or bottom of the screen. they're doing it because a) they have exclusive licensing rights to a lot of anime, so there's no competition b) they want to make money off of sublicensing to netflix and amazon, but netflix and amazon use the garbage subbing standard c) sony bought crunchyroll a while back and put funimation in charge, and funimation has never given a shit about anime
for a while they were paying their subbers to convert their good subs to the netflix/amazon shitty ones, but they have decided that instead of paying to make good quality subs for their own platform and shitty ones for netflix/amazon (or demanding that netflix/amazon update their subbing standards in order to sublicense the shows, so that everyone has the good ones), they're just going to stop bothering to make the quality subs at all. worse, it seems like they're going through their backlog and converting shows that used to have good subs over to the bad ones.
the article has a TON of examples of shows that would be seriously impacted by this change. two of my faves it mentions are kill la kill (which makes HEAVY use of onscreen text for its punchiness and humor) and komi-san can't communicate (have you tried watching the netflix subs of this? they make the show literally unwatchable. the whole premise of the show is that komi has selective mutism and talks by writing things down, and the netflix subs just... didn't bother subbing any of the text. whole entire key conversations become extended shots of characters scribbling back and forth while you have no way to know what they're saying). some others it doesn't mention that i immediately thought of were shoujo kageki revue starlight (color-coded subs along both the side and the bottom come in clutch for tracking the revue duets simultaneously with the duet dialog) and yuuki yuuna wa yuusha de aru (you need motion-tracked subs for any on-screen group chat conversation to be readable, and yuyuyu has a bunch). and the article's got a bunch more examples from shows i don't know as much about. probably you can think of some of your own faves that this would ruin
worst of all, the english fansubbing community has cratered since crunchyroll came on the scene. there's a lot more anime coming out each season, and audiences are used to day-of simulcast, and most of the really good fansubbers went pro or retired and not a lot of new ones have stepped up. so even torrenting or streaming bootlegs won't be viable for getting the speed, quality, and coverage of subs we're used to these days.
the article exhorts you to kick up a fuss - spread the word, complain on social media - and to cancel your crunchyroll account and give "subtitle quality" as your reason. it cites how back in 2017, crunchyroll tried to reduce their video quality, got slammed by their users, and rolled back the change. unfortunately, the sony/funimation takeover happened since then and that leadership doesn't seem to care at all about the quality of their product or what the fans think, so i don't expect them to respond to anything but a credible threat to their bottom line. so, maybe, if we can make a big enough dent in their subscription numbers, then they'll pay attention
and the article doesn't say this, but i'd add: complain to netflix and amazon, as well. any anime you see on those platforms, report the subs and say the quality makes the show unwatchable. consider canceling your subscriptions to those platforms as well, and citing the awful subtitle quality in your reasons, if the main thing you use them for is anime
and consider getting into fansubbing! aegisub is free and you can learn how to use it! if you know japanese, you can help out with translation. and even if you don't, fansubbing groups can always use help with timing, typesetting, encoding, quality control, etc. try joining the discord for kaleido-subs and saying you want to get involved! (or even good job! media or novaworks - they're not releasing subs anymore, but the discords are still active and would be happy to help new people learn the ropes!)