why would they need to download and setup a server? can't they just log in to OP's with the client of their choice?
Even getting people to use a different messaging app (such as Facebook Messenger) already installed on their phones is difficult.
I have whatsapp and conversations and that's it. I only use teams on my professional computer, you will never see me install "work" on my personal smartphone and nobody needs a linkedin app, the website is enough.
I agree about LinkedIn and will probably get rid of it; I mostly installed it as I was going to a conference and wanted the easy option for swapping contact details using camera codes.