CPU load on End User side. Is the code compiled?

As many others, using jitsi meet on a old/small processor PC is challenging, please understand almost impossible.
I’m just an user, not a dev at all, but as per my understanding, some code can be compiled while other may just be interpreted. This make the world completely different.
Are all the executed code compiled (in this case, adjusting quality, … as explained in other post remains the only option) , or is there any part interpreted that can be expected to be compiled in the future ?
Would it be possible to have a “compiled” client for light hardware configuration, making jitsi meet light hardware friendly (working on a sustainable way…)?
Thanks in advance for you explanations.

PS: I just found some explanation here on how WebRTC works and may change in the future, but unfortunately, not really able to understand all of that…