And as a quick edit: none of these examples I have were of failing businesses. Each of the owners had their reasons, but none was due to it being necessary for survival. PE on hackernews tends to focus on software/bigger purchases, but so much of the damage in my opinion is on the local and smaller scale.
Let's say you make an app for first responders. Being a former first responder, you know exactly what your users need and what the workflows should be like. Your app becomes a brand name in the community. You charge enough to survive (if that), because your app is a labour of love more than anything else.
Eventually, family and other responsibilities get in the way, and you just no longer have the time or motivation to maintain the app any more. You sell to "we so swear we are not private equity" Applause.
As soon as you do that, the app gets taken over by financiers and developers who are experts at "revenue optimization", with little domain knowledge about what first responders need. They calculate (probably correctly) that they can milk their customers for a lot more if they move to a subscription plan, gate some features behind expensive premium packages, stuff the app full of upsell pop-ups and fill it with analytics SDKs that tell them which features are worth spending development time on, and which can safely be removed.
The Applause thing is absolutely real though.