When using the /ride command to mount a boat, your rotation adjusts so that you face forward, similar to manual mounting. However, this behavior does not extend to mobs such as horses, donkeys, mules, skeleton horses, zombie horses, llamas, or camels. When mounting these mobs using the /ride command, your rotation remains unchanged, leading to inconsistency.

Steps to reproduce

1. Place a boat

2. /ride @s mount @e[type=minecraft:boat,limit=1,sort=nearest]

3. /summon horse ~ ~ ~ {NoAI:1b,Tame:1b}

4. /ride @s mount @e[type=minecraft:horse,limit=1,sort=nearest]

Observed: When mounting a horse with the /ride command, your rotation remains unaltered, whereas it changes when mounting boats with the /ride command.
Expected: The command should either consistently adjust the direction when mounting all these entities or consistently maintain the direction without alteration for all mounts initiated through the command.

Note: Both behaviors offer advantages for map makers, but due to MC-101980, manual rotation adjustment isn't feasible. If MC-101980 were resolved, manual rotation adjustment of the mounting entity would become possible, rendering the automatic rotation change redundant for the /ride command.