Donald Trump's promises will not increase scams because he only promised to promote self-custody. This means people will be allowed to keep their coins in non-custodian wallets without restrictions. Celsius and FTX  bankruptcy was not as a result of self custody but centralized custodian services offered by these firms. So if Trump wants people to have the right to keep their coins, that's a good move towards decentralization.

Just checked unverified data from a website and discovered that close to 40% of Americans own crypto. This information might not be accurate, but a high number of US citizens support crypto. So Trump is targeting to gain the support of this crypto-friendly population.

The news that Bitcoin mining massively affects the environment negativity is mere propaganda to discredit the sector. Other activities have a massive effect on the environment than mining. I am sure that many US citizens are now aware that all the data on Bitcoin mining power consumption are overblown.

Politicians want to gather support from all the sectors of the country. Only the votes of the crypto community will not make him win elections. But it can add to the number of his votes which can make him elections.