Am I missing something, or does it only cost about $2.27 per month to store all the tiles in Amazon S3? They're definitely not the cheapest game in town.
(Your build example says the tiles are 99GB, and their normal tier is $0.023/GB)
I guess the part of the cost that people actually care about is the bandwidth. How do you suggest dealing with that part of the problem?
Planetiler isn't for hosting tiles, but generating them. For a planet-scale tile generation job it's the difference between hundreds or thousands of dollars in VPS fees and being able to generate them locally on a modestly equipped desktop. Planetiler does drastically reduce cost in that respect.
There’s a python utility to convert mbtiles to pmtiles, but I’m also planning to add native pmtiles output to planetiler soon [2].