For us Linear (https://linear.app/) was much much better than all the competition

Two startups I’ve worked for uses Linear as well, but is it really scalable though? Like is there any big company (200+) using Linear?

[I work for Linear] Yes, we have multiple scale-up/enterprise customers with 200+ users

That's a very good point. First time I've used Jira was in a company with 500+ employees, things such as hiring were managed through Jira as well.

Microsoft's project management tool is Azure Dev Ops (used to be called Visual Studio Team Services), I found it pretty comparable to JIRA for the most part.

I used Azure Dev Ops at my last job! I thought it was fine – though I think some aspects of it weren't intuitive (maybe an unsolvable problem for a PM tool). Our team standups occasionally included someone discovering a useful Dev Ops feature that was simply hidden too well.

But the tool felt fairly fast and did it's core job pretty well.

Anyone know why they called it that though? Much of its key functionality has nothing specifically to do with DevOps, and I somewhat doubt it really supports everything DevOps (in an Azure world) requires...

I remember that Jira had a kanban board or something like that. It was almost 10 years ago. If it still exists and you're using it, give a try to Kanbanize. It's something that I almost really liked to use. The team bootstrap was done by a guy that really knew it well and kept managing and coaching for months. No idea what it would look like to start using it from scratch.