Hey there,

Foot tapping is helpful but not necessary for learning timing. It's probably better if you use a metronome.

Also, if you have not already, we have a really great lesson on timing here: https://www.guitartricks.com/lesson.php?input=23532&s_id=1914

And usually foot tapping is associated with the beat of the song, and not necessarily the strum. This is important because strum patterns can be on the off-beats and if you only tap your foot to keep the timing with the strums, you can get confused if the song is a bit fast or complex!