Due the the size of the default system prompt you get over 100k really in easy in Claude, and because that is fixed 200k is really almost 3x more room to work with, not 2x.

200k also used to be the limit for Sonnet for a long time.

If Haiku 5.5 also had 200k, it'd actually be usable for us. As it is, it's Luna or Sol.