Mobile games are not by definition bad.
Desktop games had a phase years back where everyone would release whatever games of any quality, leading many people to lose faith in the industry. This is how platforms with quality control were created.
When mobile became the new platform to develop for, there were very few rules. This means that as long as an app doesn’t harm the user’s device, it will be allowed to be published, regardless of its quality. This leads companies to releasing multiple new projects a month, which generate revenue for them.
This is what gives mobile games a bad reputation. It’s not that mobile games are bad, it’s that there are people out there working full time trying to reach the top charts regardless of the quality of the project.
There’s plenty of amazing quality mobile games, but most likely they’ve spent less time on manipulating the algorithm, and more time on increasing quality.