Only you can justify it. You’ll see anyone in this thread who bought one justifying it and anyone who hasn’t bought one doing the opposite.
It’s your money, provided you can afford it then no one else can tell you how should spend it.
Is it expensive? Sure, 700 for a console is a lot of cash. The 20% Very offer kindly posted here helped bring it closer to 550, selling my OG PS5 for 275 helped get it below 300 but that’s only me justifying it to myself.
I also just really like playing games on my PS5. I use my PC for fps games but the majority of my gaming is done on the PS5 so I’m really happy to play the games I enjoy with varying improvements. F1 24 feels like a genuinely new game, Horizon looks insane, and I’m excited to see what updates keep coming to other games.