Rob (Gfron) has more experience of running a restaurant than I have, but I've closed a couple...for what that's worth.
I think everybody who has posted upthread has amply made the point that it's a very, very risky time to launch a restaurant venture. There's likely to be room in the market for "early mover advantage" once things loosen back up, so there's that on the positive side of the ledger. Much of the former competition for your diner's dollar will have collapsed, and people certainly *will* tire of the fast-food chains before this is all over, and even if the numbers are smaller than they were pre-COVID there'll be less competition to divide up that dollar. So for the survivors (and gutsy new ventures) the metaphorical pie may well prove big enough.
That in no way invalidates anything that's been said above. Deep pockets are essential, and Rob's recommendation of a full years' operating expenses in the bank on Day One is probably the best advice you'll get (lack of capital is what scuppered my two establishments). If you *do* opt to move forward, nail down every conceivable advantage you can get on your lease (or is it a purchase?) of the current diner. Most of the value of such a business applies only if it's a "going concern," which is no longer the case.
Remember, the industry-wide average is 5-8% retained earnings, so every dollar you save up front on your fixed costs is like $90+ in revenue.
