@Michael OverallQBI number is not some "loss" that you can benefit from.It's simply an FYI number that prevents you from taking a QBI deduction in the future because you had multiple years of prior losses.Short story: you're not missing on anything.

Quote from @Santos Lopez: I heard that there's a way to deduct short term rental losses against earned income (e.g.

I have never sold at a loss.

If you already have a loss, cost segregation can make it a much bigger loss. 

If those expenses truly didn’t reduce your taxable income, it’s likely due to the passive loss limitation.So what does an LLC actually help with?

I recommend you find a CPA that understands how to do taxes for real estate investors.Generally S-Corps are pass-through entities, so I suspect his losses could off-set your W2 income.  

That usually creates a loss or brings rental income close to breakeven.If you end up with net income, then the 20% pass-through deduction might apply, depending on how the IRS treats rental income with limited personal use. 

Normally, Real Estate is considered a Passive Loss when it comes to depreciation of the building, and any other expense.

That means their share of the gain/loss could be based on the original purchase price, which can create a split basis situation between you (inheriting your share at stepped-up FMV) and them (keeping their older basis).On the other hand, your portion that was inherited at your parents’ passing would get a step-up in basis to the fair market value at that time.

If it is active, you can use the rental loss(Expenses in excess of income) against your other form of income such as wages, interest, dividends, etc.