Every time I’ve worked at a company where teams started picking their own hardware and expensing it, it ended like this. It usually started with reasonable orders, but once some teams notice that expensing hardware is working they try to push the limits of what they can get away with.
Ended up with weird situations like software and accounting people rocking those ultra expensive Apple cinema displays while sitting in their new Aeron chairs at their motorized standing desks which were always in the sitting down position.
Then someone gets shocked by the office expense line item at quarterly review time and cuts it off for everyone to try to balance out those expenditures for the rest of the year.
So we’d have a few people in the office with tricked out workstations and high end gear and then everyone else was on the same generic monitor and chair that was decided for the whole company long ago.
Even the most generous company I worked for that made a point of supporting engineer’s workstations eventually had to cut it off and standardize because the purchases were getting unjustifiable. There was also a lot of stuff like nice monitors or computer upgrades “disappearing” where you couldn’t really pin blame on anyone, because it was actually common for people to swap hardware around.
The only sustainable solution I’ve seen is when engineering gets together and argues for a reasonable set of computer gear and also a phased upgrade plan that doesn’t involve one giant expenditure in a single quarter.