The better question is when Jitsi option too.
nostr:npub18q57qr3t07qljnapzqldaqa7ru2qwfpfnjdrwvhk327n3sc82f0qqwrs6f nostr:npub18s4zkd0wjq5gkthz4paw2704ty4s354wcp2krvxy0sewz3g9z2cs73ydrt for a company that advocates for “a better internet where privacy is the default” why have you added Zoom meetings to Proton Calendar? 
Discussion
My guess would be it is quite a bit of work to host jitsi for proton customers at scale, and performantly. Whereas plugging into zoom is low hanging fruit without technical challenges.
I just drop a jitsi link in the description when I add participants
but I have my own instance so nobody has to sign up