It is forbidden to use steps to climb up to the altar

Exodus 20:23 "Neither shall you go up by steps to My altar"

The altar on which the sacrifices were brought was very high and there was a specific way for the priests to get to the top.

HaShem wants the service in the Beit HaMikdash to be refined and modest. The slightest detail is taken into consideration - even how a priest gets to the top of the altar!

Instead of steps, which require lifting one's feet high off the ground, we are commanded to build a ramp leading up to the altar.

On the ramp, the priest can take small strides in a dignified manner, as befitting one who serves in the Beit HaMikdash.