Unfortunately this might not be true. Instances need maintainance. If the one that spun it up doesn’t dedicate time and resources to it your experience might just be worse than average.

In my case I was having all kinds of timeout issues and occasionaly instance went down. Moved to a bigger and more active one and never had issues since.

People complain about Firefox performance and site compatibility all the time and I have no idea what they are talking about. I use both it and other browsers all the time and Firefox for me is the better one.