What are the pros and cons of working in a product based company?

Nothing inherently wrong.with a product based company. But not all companies are the same.

Microsoft or Google or Adobe have dozens of products, so if one falls out of favor or gets competition, they have lots of cushion to gall back on.

A company like Slack or a lot of the app-based companies are one-trick ponies. If their software gets competition, they may fail.

So the real answer has to be “it depends”