I run (one of three partners) a small IT company in the UK. I’ve always Linuxed since around 1998. After messing with RedHat, Mandrake, Yggdrasil and others I settled down and ran Gentoo for many years and then Arch for some more.
I’m gradually dumping the Windows servers and replacing with Linux based beasties. We are also in the throws of replacing VMware with Proxmox.
I also have a pretty decent Kbuntu based desktop/laptop effort. I’ve done Windows client deployments in the 1000s so I have quite a good idea about compliance etc. An Ubuntu based box can run several AV solutions, secure boot and full disc encryption. Buzz words perhaps but also audit points and will get you over the line for Cyber Essentials Plus (UK).
Libre Office works for me and I used to teach office suites in the 90’s! Things have moved on since but a decimal alignment stop is a decimal alignment stop today too (do you know what that means?). I run our Exchange system, and I migrated it from GroupWise back in the day because the kool kids “required” it. Anyway, Evolution with EWS will get you full functionality for a client but with far less faff.
I’m taking my time. I already have at least two employees who are dyed in the wool Windows officianados begging me to migrate them to Linux. I will but it takes time. For example - “drive mappings” or in English: Remote mounts.
CID - cid-doc.github.io . This is an easy to add Windows compat thing. Its rather good. For static desktops its fine but for laptops that move around a lot it can be hard to get the file system mounts working again quickly in a dynamic environment.
CID uses a PAM mount based system and in the past I used another one (autofs I think). However it seems to me that mounts are not dynamic or responsive enough. In the end it is Samba and that might need some fettling as well.
As I said earlier, I’m taking my time (I’m an engineer) but be assured that Linux is quite capable of driving your desktop.