1. registration popups (newsletters, membership) and paywalls that appear when I click on promising links.
2. cookie banners, popups, interstitials that pointlessly require additional actions everywhere, like a stupid second door on a fridge.
3. stuff that is broken because obscure JS / new non-standard browser feature doesn't work, possibly because of ad/tracker blocking.
4. copyright scares and other legal obstacles and uncertainties for publishers (e.g. GDPR) that drive smaller, especially noncommercial publishers away from the web, so users become easy victims of multinational corporations with predatory business practices. This is a much bigger issue than hacking for small publishers.
What do "polarised discussions" even have to do with the web? We have them in every pub. The fact that they're prevalent on the web is a sign that something works, not the opposite.