A common reason for IntelliJ to freeze is not giving it enough memory, which causes frequent GC stalls. You can try increasing the max heap by following the instructions here: https://www.jetbrains.com/help/idea/increasing-memory-heap.h....

I gave IntelliJ over 8GB Ram (on a 32GB laptop) but keeps freezing because they say it's a Linux kernel problem in the 5.4 (shipped with Ubuntu 20.04/Mint 20)

I see such issues on larger multi-module projects. A very reproducable example would be something like Presto (https://github.com/prestosql/presto) or Debezium (https://github.com/debezium/debezium).

I've increasing the JVM heap as much as I reasonably could but giving 2GB of Heap to an IDE on a 16GB system seems wasteful.

The only thing wasteful here is paying for 16 GB of RAM and then deciding to arbitrarily restrict your primary productivity tool to using 1/8th of it.

I have seen quite some companies. and everywhere the same thing. intelij once the beloved replacement of eclipse now gives the same experience as eclipse. insane in memory use. constant indexing and slow scrolling ui's. spontaneous hanging and frustrating slow code hints. now I admit that it's also a combination of many tabs in Chrome, using docker etc. hell everything became slower last few years. CPUs just didnt make enough progress I guess.

It’s quite easy to make any JetBrains IDE stall if it’s resource constrained. It needs a lot of memory and a _lot_ of file descriptors.