Is There Any other option to replace TapaTalk
Sort of - use your browser. It's fully responsive and looks/works fine on mobile with the exception of not having push notifications when accessing via the web.
Tapatalk isn't hugely liked by many forum admins - we ditched it on my own forum due to worries about the unfettered access Tapatalk has to forum/user data, plus the lack of control over the app or monetisation. Responses from staff were so slow and the whole company seemed too vague about things.
Unfortunately there doesn't seem to be much competition but I am surprised a site with Mac Rumors' clout doesn't have the funding/desire to get a custom-made app sorted.
As stated above, a major headache for forums has been the lack of push notifications on iOS (in Safari) which has stalled proper development of the forum via a browser, but this is supposed to hopefully - finally - be coming to iOS at some point. Then, accessing forums via browsers should give a similar experience to standalone app.