Being in the IT business for a few decades, email is superior to anything else for record keeping. Especially with Thunderbird I find it almost too easy to find information I need, and addendums neatly threaded.
And, it is quite difficult for the other part to hide/delete stupidness they send, which thankfully saved my behind twice.
Chats are good for now-communication, but energy- and time consuming when you need to look up something that happened months ago.
Gmail is dogsh*t at search. It's so bad. I can search the EXACT word I want and not a single email will come up, or it will bring up the most irrelevant emails.
Same experience and it’s so bad I sometimes question my sanity. At least I have a notmuch index setup on a server I can fall back on but it’s just so bizarre a “search” company can’t produce an app which can search properly emails!
The worst part is that I pay for the privilege!
I can't even look up chats on my work PC older than a couple days ago because it's automatically deleted. Emails last for at least a few years.