"Is launching multiple startups a good idea?"
I absolutely do not think so!
Why do you want to have multiple startups?
Do you have brilliant ideas and solutions to problems in more than one field?
Are you spreading yourself too thin?
In case of a crisis at more than 1 startup, how will you prioritize?
Will every startup have their own CEO to run the business? Then are you a founder or an investor?
Please dont quote Elon Musk when you're bootstrapping startups and need to raise funding. He did it by putting his own millions. He works 100+ hours a week. He's sometimes also a wreck!
Investing is a lot like running a business. Just like an entrepreneur has customers, an investor has investee companies.
Does an entrepreneur just keep selling without paying attention to churn, or customer satisfaction, or growing client accounts? No!
Similarly, an investor just doesnt keep new companies all the time. Investors also have to look after investee companies, how they are performing, how can they be helped to grow, and look after their founders!