With any change on the site formerly known as Twitter, there are 3 lenses to examine it through:

1. Reducing the massive financial loss that Musk will almost certainly take
2. Amplifying the voice of the far-right
3. Stroking the ego of the man child who owns it

This is probably mostly 1. He's looked at the number of users and said "what if they were dollars?".

But like you say, there's probably a bit of 2. Reactionaries are more likely to hand over a dollar for a Truth Social with outside their choir to abuse.

It probably won't dissuade bots and astro-turfing, but it will make it pay-to-play, with the richest welding the most influence. That's definitely 3 since by any other metric besides money, Elon is average.