My guess (complete speculation, but I worked with the Search Quality folks about a decade ago):

1 - By interpreting your search, it leads to better "search quality" by having one model say "i think this is what they want" and another execute the search. P90 accuracy is increased at the cost of P99 accuracy.

2 - If you search for a literal string you know exists, you expect to find it. By interpreting, fewer search inputs with literal strings make it to the search function.

3 - Since Google is interpreting more searches, this gives ad-placement a route in to favorably interpret "they want to buy something" even when this isn't the case. This makes Google money.

4 - People that used to use literal searches either stop, learn how, or switch search engines.

5 - After a couple years, business metrics show that literal searches represent 0.1% of queries and make less money, is it really worth investing in? When it was a P99 issue it fell off the radar and now the P999 is lost.

So a series or rational decisions by rational actors leads to a decline of a used feature because of business incentives and chasing P90s at the cost of P99s.

So they're basically just as good as some malware search engine that inserted itself into grandma's computer now

Fantastic

At least those entertained people.

I couldn't get my fiancé's mother to stop re-installing bonzi buddy or whatever that toolbar was called because she 'loves the purple monkey, he's so cute!'

Man that's crazy in the early 2000s I was volunteering with developmentally disabled adults and had to explain to them how bonzi was a 'bad monkey' and that he was 'not a friend' and they got it

It's also possible they they're correct, and the average user of today has much less need for verbatim searches than the average user when the search engine was first designed.

Nah their product is broken and I'm going to avoid using it from now on except when I need to find something on a map or mess around on SEO for work

If they break a key feature to MAKE a verbatim search happen with literally two keys pressed, and are apparently not even indexing what they used to anymore, they're dropping the ball. Most people know the quotation trick now and are probably assuming it still works

The quality of search results I get from Google has seriously degraded over the past several years (I think about the time they decided to start interpreting my searches rather than just search for what I asked for). From my point of view, verbatim searches are more necessary now than ever before, to work around that issue.

I tried using verbatim searches to make Google decent for me again, but Google defines "verbatim" rather differently than I do.

This is definitely the case. Sit down next to a casual user one day, and you'll find that 'verbatim' is the absolute last thing they need.

This is almost certainly the case. Those of us who learned to use and mastered keyword-style search are the minority. Most people search whole phrases, expecting a contextual answer.

Yeah, it's Google. I feel like, at this point, Google is basically synonymous with "bad decision"