I may not be the best person to respond, as I've also never leased before. Normally I buy my vehicles outright. I'm leasing only to protect myself from Lucid failing (which seems somewhat more likely as Gravity demonstrates how bad their software engineering is) and to provide an easy out in 3 years if my Gravity ultimately turns out to be buggy enough that I regret buying it. The $7500 incentive compensating me for some of the financing cost helps make the lease more appealing.
In California, you pay sales tax on each lease payment, 7.25% in my specific county. That is baked into the $1703.39 in my quote, so there's no sales tax charged beyond what is quoted. An online lease calculator breaks the monthly cost out like this:
Monthly Depreciation: $1,378.99
Monthly Interest: $209.25
Monthly Tax: $115.15
You can probably argue about what the right mindset is for comparing the leasing tax costs to the cash purchase tax costs. If the vehicle works out well, I may well purchase the vehicle at lease end, paying sales tax on the residual value, and effectively having a wash on tax cost. Leasing still has a tax advantage, as I don't pay tax on the $7500 discount ($6505 net after lease acquisition fee), and the time value of money for paying the sales tax on the residual value in 3 years instead of today.
All that said, my own personal calculation is that if I buy the vehicle outright, I'm spending $56,148.75 for the initial 3 years (vehicle cost + destination fee - residual), and if I lease I'm spending $57,176.64 for the initial 3 years (36 payments, less the $115.15 monthly sales tax). So leasing is $1027.89 more. Obviously a full time-value-of-money calculation will change that somewhat, as will comparing a financed sale instead of a cash purchase.
All in all, I feel like the protection I get from leasing gives me a hard-to-value insurance policy that is worth it.