That is true of course, although I would think most competent rate limit implementations would set thresholds that deter bots while real users barely notice, unlike what was observed with twitter. Coincidentally, higher rate limits were a paid option. Spam might not have been the primary motivation for rate limits.
Elon Musk said it was due to "data scraping and system manipulation":
Rate limiting is literally a way to reduce bot attacks, which is a key tool in spamming campaigns.
https://www.cloudflare.com/learning/bots/what-is-rate-limiti...