Your house might need gutters, dirt at certain locations where water is pooling or maybe just have the tenants water the yard.

Speaking of a soak, it’s always a plus if the property has a pool or jacuzziWhile a swimming area might increase your HOA fees, it will also increase your average nightly rate and average guest satisfaction score.

And if people can't find homes to buy, doesn't that make them renters, and thus the rental pool continues to get bigger?

You could do better throwing darts at a chart on the wall.The response to a seller wanting above actual market value is to first show them Zillow's claimed accuracy (hover over the word "Zestimate" for a pop-up disclaimer) and then to show them actual comps.Things like this are the reason that Realtors hate Zillow and their Zestimates. 

Here the comparison chart after 20 years...

That’s with 3 pool pumps and a electric car. 

Tenant pools tend to be less of a headache in more affluent areas.

Some turn-key providers send out a list of properties (up to 5 properties a week) to their investor pool which get sold within 10 minutes of when they are posted (is the market really that hot?!)

If it's something common to that market that buyers will pay more money for, then they'll include it in their opinion of value.Another example is a pool.

We thought it would be a no-brainer to have it comped to SFH+ADUs in the area since the front house (3bd/2ba) is 3x the size of the back house (1ba/1ba), and the property has a pool, but after multiple appraisals they've all comped against other duplexes or "two on a lot" properties and the value just hasn't been anywhere close to a SFH+ADU.