Haven't used Tapatalk but FC's mobile site is a joy to use. When I use Firefox on my laptop it renders the text to ant size proportions. It makes me use my phone to browse the site.
You probably have a nice, high DPI screen on your laptop. You can increase the page/text size in Firefox by pressing CTRL and + at the same time or by using
some other methods.
Regarding Tapatalk, I prefer to avoid running third-party code on this site whenever possible, especially when it requires full database access, and even more so when it's written by developers with a long history of bad coding and major performance/security issues. Tapatalk caused massive issues for us and others and the problem wasn't fixed or even acknowledged for months.
The company has repeatedly released new versions of the program, requiring customers to buy it again instead of updating existing versions, and reliance on a proprietary, closed source program to use forums is not something I want to to encourage or support.
I know that some people prefer a native app to responsive design, and in some situations a native app can provide useful functionality such as push notifications. Responsive design has a way to go, but it is the way forward. It works for every mobile device with no installation or purchase required and browsers are getting closer to device-centric push notification support. The Xenforo devs also have a way to go when it comes to the editor, and their responsive design implementation could be improved upon. They are some of the best in the business however, and I'm sure we'll get there.