There is no data on the issues that may pop up with Tesla ownerships over 20-year life cycle. Because the car has only been around for <5 years, and most Model 3's are still covered by factory warranty.
Tesla's warranty is 4 yr/50K miles for everything (similar to all luxury brands), and 8 yr/100 miles for powertrain (whatever is included in that). The challenge is taking advantage of that warranty, as Tesla's service center footprint expansion has been lagging far behind the growth in vehicle sales. In my neck of the woods, appointments can be scheduled only 3-4 weeks out. If it's something minor (e.g.: my passenger seat buttons keep falling off), this is bearable. If it's something major (suspension of drivetrain problems), you will need to fall back on a second car, or a rental, while you wait for your appointment window.
For that reason, I have recommended that my parents (and others on fixed income) avoid Tesla ownership. Things do go wrong with Tesla's at a higher-than-average rate (per Consumer Reports), so this "fewer parts to fail" logic falls short when the fewer parts fail more frequently (e.g.: universal front control arms defects). And when things fail, the service delays will be a major risk factor if it's your one and only car, and you have to rely on it for daily transportation.
Insurance rates are also significantly higher on Tesla's than comparable luxury cars. Never mind a Camry.
HTH,
a
P.S.: When you do have to pay for service, everything Tesla costs 2-3x what you would have expected. Tesla's monopoly on parts and body shops is a major challenge for post-accident repairs as well.
P.P.S.: See this thread:
Tesla cancels appt [due to lack of parts - upper control arm]