Just... no.....
30 FPS is probably fine for nature, people, etc. but if you're dealing with anything with higher frequency motion it sucks.
I didn't say 30FPS looks more or less the same as 60FPS, but AFTER CONVERSION (properly), it can looks like native 60FPS video without significant different.
I did that many times in FCPX (use optical flow analysis). I can even convert a 24FPS video (from the very old iphone 4) to a 60FPS video which looks like record at 60FPS natively. Of course not all video works, especially if there is a sharp straight line in a very fast moving scenes. That straight line may shows artifacts after conversion.
May be because I am just a normal user. Most of the time, I am just making home video, but not recording something like motosport. So, I prefer more details than higher FPS. Especially there is an effective way for me to "fix" a 30FPS video to 60FPS, but no "fix" for 1080 to 4K.
Therefore, if I can only choose one format (and no idea what kind of video is going to record), I will choose 4K 30FPS over 1080P 60FPS. This is mainly based on the "possible fix". However, if I know that I need 60FPS in the end (e.g. recording motosports in your case), I will still prefer to record the video at 60FPS natively, so that I don't need to do any conversion afterward.