It makes it real difficult to extract all of the investment. 

I personally feel comfortable if my total LTV is at 75% or lower but in practice I am typically far lower than the 75% due to the cost/effort to extract equity. 

Saving on taxes when extracting the profits is a different subject.

The longer the holding period, the higher the cash flow (assuming no value extracted - My actual cash flow is not as high as it could be because I have extracted a lot of value via refinance from most of my RE).

The simple business model where an owner lives in a big house, extracts value from their employees/1099s, practices multi generational nepotism, and encourages unethical business practices by bidding 30x projects at 400% margin to get that one project from poor ol Betty Sue - this is what needs to change to get more ethical and capable entrants into the trades.Anecdotally I haven't really noticed reduced supply in my market, but we've developed some helpful relationships over time with our go-to plumber, among others.

Use the extracted money to repeat. 

So, we developed our own capability to extract and display SFR rental data for the area we target and a property profile that rents well to our target tenant pool.

See your state and federal laws prior to extracting any possible hazardous waste.

I'm still single in my late 20s and I don't want to over stretch myself at this stage of life.On the other hand, I can extract my equity out of one of my rentals to support another buy.

It is up to the buyer to read the contract and extract the address from it.