https://www.techspot.com/news/77482-internet-evolving-http-no-longer-use-tcp.html QUIC has been built upon UDP (User Datagram Protocol), which is leaner than TCP, but lacks some much-needed features for a safe Internet. UDP doesn't incorporate Reliability (knowledge of missing data from the origin point), or Order (meaning that data is received in the order it is transmitted), things that TCP does include, right alongside Error-correction (detection of in-transit corruption of data).
The problem with TCP is that it includes many more features that really are not required for today's ubiquitous internet protocol, HTTP (HyperText Transfer Protocol). That's where QUIC comes in: it's a more complete version of UDP, with the required TCP features (and only those), alongside some "under the hood" improvements of responsiveness and latency improvements. One of the most important features for HTTP built over QUIC (HTTP/3) is that it should be able to fold both connection and encryption requests to servers in a single move, which otherwise require multiple round trips of data over TCP - halving latency for newly-established connections, and reducing it to zero over already-known ones.
Any improvements over the current HTTP protocol is fine by me