It's important to conceal your identity because the internet is forever. Your comments, opinions, beliefs, embarrassing moments... all recorded (essentially) for life. This happens through administration changes, different jobs, life changes, belief shifts, different friends and partners, etc. Without anonymity, anybody can comb through your entire history to make any point they want. To justify any accusation about you they want using 'evidence' from years past. To stalk or harass. To fire you for daring have an opinion about something. Depending on your government, to arrest you for what you've said in the past.

A huge issue with the modern web is that everything is seen as a profit motive. I don't care how many billions of dollars tracking everything we do and tying it to our person is worth. I don't want it.

And hostile regimes can surveil, harvest, and buy up data to murder their opponents. "It can't happen here" is always naive "logic".

That's a good thing since it means we have the opportunity to be remembered for eternity. Information is permanent. Also don't think that just because the system doesn't reveal who you are to other users today that your identity and life activities won't be decloaked later on should culture or policies ever change. If you're open, trusting, and use your real name today, you'll at least get the benefits and glory of eternal fame while you're alive.