PC is the absolute best platform to play a good majority of games. That's not to mention the hundreds of thousands of fan mods, all the emulation possibilities, or even genres that are damn near impossible to play on consoles. I can play just about every game of the last 40 years in the absolute best fidelity. It's the greatest platform around.
But it can be an investment and the initial cost of entry for enthusiasts-level gaming can be higher than what you'd pay for on current-gen platforms.
If you have everything to play games on and are disinterested in playing games from across the gaming pantheon on one platform, then no, I'd say you don't need a PC. But there are some aboslute amazing classics that still hold up today that can't or shouldn't be played on consoles and that gulf will only grow wider. I can say I've literally had every major console since NES up until the most recent generation of consoles, and I still felt compelled to get a PC when I did because I felt like I was missing a whole side of gaming that I really had no experience with. And when I finally dipped my toes into the water, it was very difficult to go back. Just the amount of choice and options of how you can play any given game gave me reason to go back and replay old console games I'd played dozens of times already and found myself having even better experiences.
Really though, play what you want. Is it worth it? Yes, but understand that there'll almost certain be growing pains and googling that you hadn't really expected to do. But I find it well worth it. But generally, just play on what you can afford and don't try and keep up with the joneses. If you feel like you're missing out, maybe there's a whole new avenue of gaming waiting to be discovered, and maybe that's what's got you so intrigued.
Consoles aren't going anywhere and will ALWAYS be the platforms that 85% of games are designed around. PC just takes all that and adds a cherry on top of it. A sundae is nice, but a sundae with sprinkles and cherries is nicer.