Using the car will result in patination both exterior and interior. It's up to the individual to decide how much they accept and how much time/effort/ money they spend on maintenance.
Unless you coccoon the car and don't use it you will get marks.
This doesn't worry me as I want to drive the car so accept patination. Some is easy to treat, some need more effort. It's up to the individual to decide.
After 7.5k miles in year 1 I have touched up stone chips, cleaned the leather, washed/waxed etc. Having a garage makes this easier and prevents weathering issues.
I didn't spend £££££ to keep it tied up in a garage and depreciate. It has and will depreciate more but the enjoyment mitigates that. Morgans were one of the lower depreciation brands but not as good these days. Cars are not moving in the market and expectations of past depreciation- beating are no longer there. Owners are being over optimistic on selling value. A Morgan sitting and not used is a sizeable chunk of dead money that isn't increasing. Enjoyment is your payback.
Advice? Get what you like and deal with arising issues. Don't buy as an investment as that only applies to very few cars with exceptional provenance.