How much are you paying your engineers? 3% of burn sounds pretty low, but it's not completely out of the range of what I just penciled in here. (I was prepared to disagree... but the numbers aren't crazy on either side.)
Our #1 expense by a massive margin is employees and associated benefits. #2 is probably the combined cost of hosting and SaaS services we use (AWS/OVH/DO/Vultr, Gusto, Xero, Slack, Zendesk, etc.). #3 is probably a tie between travel and other incidentals like accounting and computer hardware, and our coworking space. The rest is change.
I guess some people just splurge on office space. I don't know what kind of office you'd have to be getting for it to even approach labor cost for a startup. Personally if I were an investor I'd do everything I could to veto that since it's insane and wasteful.
Does it help with recruitment? Maybe, but personally I'd rather work for a hip company in a garage than a boring company in a posh office. Maybe that's the problem.