PS4 game sharing, what are its advantages and disadvantages, and is it legal or prohibited?

I recently discovered a video by chance called PS4 game sharing and PS-Plus, but how does it work, what does it take to do it, who would do it? And how certain is that, or what do you have to give up for it or something and is it worth it?

I would be very happy if every PS4 player or general console friend or fan gave their opinion with a reason and the advantages / disadvantages.

LG, thanks in advance! 👨💻✍☺🕹

I have been sharing Ps plus and playing with friends for years, is actually quite simple, just type in Yt, nothing will happen