Seconding this! I'm nowhere near a masterful player, but having the rankings helps me decide what conventions are likely to be understood at any given table, and guides how I might go about interpreting clues from other players ("are they discarding this to send a message, or is it because they don't know how many 4s we have in the deck?").
It also helps with facilitating mutual support and camaraderie - seeing ELO helps me to figure out whether it's appropriate to offer advice (for example, if somebody has an ELO of under 20 or so I'll let them know they're welcome to ask any questions), or whether I might actually ask for guidance from them if I feel like they're doing something fancy that I'm not picking up on (which is how I've learned many of the conventions that I now know!). Right now I'm hesitant to say anything, lest I insult somebody by incorrectly insinuating I know more than them.
This applies to other co-op games as well, like Burgle Bros and Now Boarding! ELO is a tool that helps guide understanding about who you're playing with, and it's a pity to lose it.
And let's be honest - the kinds of people who engage unhealthily with ELO scores aren't going to stop just because there's only a tier displayed instead of a number.