Would you refuse to visit websites that force registration even if the account is free?

I already generally do.

What’s all the fuss about, you don’t care?

I honestly don't much care, but that's because western civilization is circling the drain, warped and undermined at every turn by wealthy and powerful psychopaths, and it's just not worth it to care, since there's absolutely nothing I can do to stop them

Is advertising a necessary evil in fair trade for content?

Some sort of revenue stream is potentially necessary, but that's the extent of it. Advertising is just one revenue stream, and even if we limit the choices to that, there are still many different ways it could be implemented.

The specific forms of advertising to which we're subjected on the internet are very much not necessary. And they don't exist as they do because the costs of serving content require that much revenue - they exist as they do to pay for corporate bloat - ludicrously expensive real estate and facilities and grotesquely inflated salaries for mostly useless executive shitheads.

Would this limit your visiting of websites to only a narrow few you are willing to trade personal details for?

Again, that's what I already do, so it would just add more sites to those I won't visit.

Is this a bad thing for the internet experience as whole, or just another progression of technology?

At this point, the two are almost always one and the same. Internet technology is primarily harnessed to the goal of maximizing income for the well-positioned few, and all other considerations are secondary.

Is this no different from using any other technology platform that’s free (If it’s free, you’re the product)?

This is cynically amusing on Lemmy.

Should website owners just accept a lower revenue model and adapt their business, rather than seeking higher / unfair revenues from privacy invasive practices of the past?

Of course they should, but they won't, because they're psychopaths. They'll never give up any of their grotesque and destructive privilege, even if that means that they ultimately destroy the host on which they're parasites.