It depends on the site. For a blog PoW is perfect, however if someone like Facebook or YouTube switched to only PoW then the spam would entirely dominate and make the site unusable.

It only slows down bots. If a bot is willing to do the PoW then it can get right through.

You said “Firefox derivative” so resistFingerprinting may be enabled and WebGL blocked. If you’re talking about Librewolf, you should turn those off, then use Jshelter to get the non-breaking protection back.

Bitcoin isn’t a scam; it has value because of supply and demand and the fact there will only be 21 million ever mined, however anyone is allowed to use it.

A standard Firefox is not private and is easily fingerprintable. Those settings give you good privacy but won’'t make most captchas fail.

It should work if you use a Firefox based browser with tracking protection set to strict and resistFingerprinting disabled, then use Jshelter with the following settings.

• Locally rendered images: Little lies
• Locally generated audio: Little lies
• WebAssembly speed-up: Enabled
• Everything else including Fingerprint Detector disabled

Then visit fingerprint.com in a normal window, then visit it again in private mode with a VPN or with a dufferent server selected. You will see that the ID is different both times which proves that you’re protected.

As for the adblocker, just use uBlock Origin with the Quick Fixes list disabled as it may shadowban YouTube comments because their bot protection is silent.