I am not saying all, maybe python. Like quantopian or quantconnect. Pine script is just a syntax. They could use C++, Java, or any conventional programming language as their syntax.
I either previously use them, know enough people who use them to form a useful opinion, or demo them. Prior to trading futures spreads I used trading view to plan entries because IB TWS is awful imo. When I was trading MES for a few months I used multicharts. I started trading on TOS. For filtering stocks for my LEAP plays I still do occasionally I use filters set up on trading view because its filter package is one of the best I've seen outside of TOS and I'm not bound to a platform.
I went to interview for a Cryptocurrency Hedge fund in San Diego and they were using Tradingview- recommended for me to learn pine script. I unfortunately did not get the position since my excel skills were shit
They would never want you can just copy and paste the script to another platform and run it, so they will keep using their unique syntax.