Yes, you can avoid this by having an adblocker installed or being savvy enough to recognise what is and isn't an ad, but that doesn't apply to the majority. Just did a search now with adblock disabled, and 70% of the page is taken up by ads that look extremely similar to organic results.

Can't find the link right now, but there was a well documented case about companies who buy Google ads for things which should be provided free via the government, and slap a large processing fee on top of it. These companies end up making big yearly profits by duping people who don't know any better, and trust Google to show them relevant results, not realising that it's actually showing them the most lucrative results first.

Yeah that one might not bother you, but it's just one example... there are many more ways, some a lot more subtle, that having a primary focus of ad revenue degrades the quality of products.

On the other hand, making money from ads requires attracting users at very large scale. You can see this with Facebook and Google who try to make their product universally used, to the point where they have major initiatives to make their services available in third-world countries.

A subscription-based service deliberately leaves out people who are unwilling to pay. Even if those who do pay get better service (sometimes but not always true), there is a loss of utility from serving fewer users, particularly on the low end.