From what I've read most PHEVs tend to have really bad batteries that are unreliable, complicated and expensive to replace. It makes sense that they cut corners when there's a whole other powertrain to mask it.
My impressions had been that it largely mirrors the EV market: A few early PHEV models (such as the BMW i3) had poor battery management leading to unreliable battery packs. This was fixed in subsequent generations and is not a problem unless you are scraping the bottom of the used market. That's much the same as how EV batteries are generally reliable unless you buy early versions of certain problematic models (particularly the Nissan Leaf).
BMW i3 owner here. The i3 never had such issues and has been praised for its overall great engineering (see https://www.youtube.com/watch?v=JjPIuLz5VFI and https://evclinic.eu/2024/11/03/which-used-ev-to-buy-a-beginn...). It is also not a PHEV but an EV that had an option for a range extender.
It works. People hates it. The issues with it are mostly theoretical or matters of preferences. That's hallmark Toyota, isn't it...