They still are a strength, if you search for a public person by name the blue checkmark still works very well. But if it's commodity where scammers can buy them then the strength is gone.
What is this going to solve? Blue checkmarks was intended to find the real public person instead of thousand scammers. If it now means that you have paid for account, then what is the point?
This is not going to help their finances either. Someone [1] did a calculation:
"If one in five current blue ticks paid $20 a month that would raise just under $15 million a year for Twitter… Twitter’s current revenues (mostly from ads) are $5 billion a year. Musk’s apparent plan would generate about 30 hours’ worth of annual revenue."
Why assume that only current checkmark holders would pay? I'm sure there are many more who wish they had a checkmark who would pay. Overall, I have no idea if it's a winning strategy, but I think this analysis undersells the potential.
