If there's a washer that leaks a little bit when it runs you might then have a tenant that doesn't tell you because they don't want to pay for a repair.  

what about a plumbing leak no state holidays ?

I have seen that many,many times and it is in many cases a cash flow killer.If tenants do not pay or reimburse even they do not report water leaks which can cause higher water bills, mold, water damage to walls and floors, bug infestation from the moisture growth,etc.Tenants also use about 30% plus more resources on average when they are not paying directly.If tenants paid directly and water drips once every 30 minutes from faucet you better believe most will let you know right away!

I've had major leaks, etc. repaired this way.

All units 2br 1ba.One roof has a leak, so it needs repair or possible replacement.The street is probably C or D class in my opinion, mostly similar quality duplexes.

For example, I couldn't fix a leaking faucet if my life depended it on it.

HVAC company says I have a leaking condenser coil and suction line near case coil.

The water has not been turned on in 1 year so I am unable to see where the leak/moisture could be coming from.  

A few water heaters are beginning to leak and two sidewalks need repair as they’re cracked and considered a trip hazard.

I have a potential roof leak on my personal residence.