Sometimes those websites lied that they don’t support Firefox. For example, google meet didn’t support background blur on Firefox? Change the user agent to chrome and it suddenly worked!
As for simple stuff such as menu or elements not loading, it’s usually the dev copy pasted outdated code/css that uses WebKit/Bink-specific prefix even though Firefox already support them if they removed the prefix. Nothing we can do about that except pestering the dev to fix it or overriding it yourself using some css overrides extension.
Sometimes those websites lied that they don’t support Firefox. For example, google meet didn’t support background blur on Firefox? Change the user agent to chrome and it suddenly worked!
As for simple stuff such as menu or elements not loading, it’s usually the dev copy pasted outdated code/css that uses WebKit/Bink-specific prefix even though Firefox already support them if they removed the prefix. Nothing we can do about that except pestering the dev to fix it or overriding it yourself using some css overrides extension.