A lot of internal tools is overengineered bullshit... if that’s what they are spending it on (doubtful though - it’s probably mostly some form of sales).
For most companies I've seen, enterprise sales is what costs most money. It's worth it in the end but there's nothing you can automate around all the calls, forms and processes you have to go through to get a big enterprise client.
Yet many companies invest in it because in the end, the client is happy to pay for all your additional expenses, knowing that they can trust your service.