Lol the reason the legacy accounts had more reach was fairly simple, it benefited twitter by putting more eyes on the adverts and people actively sought those accounts out in many cases*, things like having verified weather feeds and warning accounts for your local area meant that you were likely to be checking Twitter if just as as a quick and easy way to see what it's like/if there were any warnings for your area, whilst the likes of Stephen King you'd normally be paying tens of thousands a month (if not more) to have them giving out content on your platform so getting them giving it out free was great.
The legacy Twitter engineers who actually did the work and Musk dumped knew the value of those accounts and it wasn't in getting $8 a month or even $1000 a month from them, it was getting the millions of eyeballs they bought to the platform, something that even Musk seems to be realising to a degree now with his deliberate and court case inviting confusion over the blue ticks where now there is no way to tell if you're following the real actor or someone with a stolen credit card as all the blue ticks now basically admit paid for blue isn't something of value as it's now meaningless, and that most of the old blues are unlikely to pay.
*Literally even without specific "amplification", an account with 1 million followers was always going to get pushed a lot harder by a system that took follower count into account. than a 100 follower account