So now you have all

- your storage in one place

- you own all backup,

-- off site backup (hot or cold)

- uptime worries

- maintenance drives

-- how many can fail. before it is a problem

- maintenance machines

-- how many can fail. before it is a problem

- maintenance misc/datacenter

- What to do the electricity is cut off suddenly

-- do you have a backup provider?

-- disel generators?

-- giant batteries?

-- Will the backup power also run cooling?

-natural disaster

-- earthquake

-- flooding

-- heatwave

- physical security

- employee training / (esp. if many quit)

- backup for networking (and power for it)

- employees on call 24/7

- protection against hacking

+++++

I agree that a lot of cloud providers overcharge by a lot, but doing it all yourself gives you a lot of headaches.

co-hosting would seem like a valuable partial mitigator.