Popular browsers limit the size of the URL (not specifically the query string, the whole URL). If frameworks limit qs size, it’s most likely due to upstream browser limitations.

CloudFront does as well. Bit us when Adyen didn't support a POST-workflow for our case, and at the time sent a GET request a thousand kilometers long instead.

AFAIK Chrome et al do too. at a couple thousand of characters last I searched for an answer.

I did write some tracking code that ended up having really long strings and a ton of parameters and wrote it to break into multiple requests at like 1800.

also things like proxies/load balancers. I remember being happy that I figured out how to configure my framework to allow a long url, but then sad that something in between wasn't allowing it.