TPG uses inflated valuations because that way they can call a 50,000 point sign-up bonus a "Bonus worth $1000!!!" in their headlines and attract more people to open credit cards, for which they get paid $100+ each.

That said, while the same misaligned incentive still exists, I personally find OMAAT's point valuations a bit more reasonable: https://onemileatatime.com/guides/value-miles-points/ (And, perhaps not coincidentally, he usually does not frame credit card pitch post titles in that way, though he will mention his implied valuation in the text of such posts.)

This is also not a bad shorthand (though I would bump up the value of Bonvoy points slightly).