Ps5 is like 450$ + 640$ for 8 years for Online play and you will still need to buy a mid tier PC for like 500 or so $.
You don't need to buy PS+ at all. In total since PS+ became a thing I have paid for a whopping 3 months total over random amounts of years when I wanted to trophy hunt. That's it. F2P games also don't require it. Unless you are playing CoD, Fifer, Madden, 2K, or Helldivers religiously it is very unlikely you need PS+ at all.
Why buy a system that barely runs games at 60 fps low settings
Because most people do not care unless the option for 60 FPS is offered to them. If there are no perceivable drops at 30 FPS most people do not care and this has been the case for two generations, almost three now.
a Budget PC that can barely do basic non gaming related PC stuff.
Because the AVGN meme is a real thing and if you think people want to come home from work sitting at a desk to sit at a desk and play games instead of sitting at their couch you are a very very small minority.
you also have to constantly unplug and re-plug your older consoles in case you want to play older titles.
Connected to my PC monitors right now I have a Wii U, Switch, PS5, PS4, SeX, and 360 connected to it alongside my PC. HDMI hubs are dirt cheap and it's not like you can't use a power strip or a UPS that has slots for everything important to you. A PC only need 2-3 (Tower + one or two monitors) and the rest are for your important consoles. Mine personally has eight slots to plug into, two being battery backup (My computer and my PS4) and six being for power surges (My other systems). I have my monitors on a power strip.
and will probably last you 8 years on top of having access to the entire library of old games.
Most people do not care. $1500 up front is your issue, you WILL be required to tinker with it unlike a console, having a tower at your sofa introduces a whole host of logistical issues, and most people do not want to touch graphical settings to lower stuff.