max_connections different between primary and standby: is it possible?

Hi all,
running PostgreSQL 14, physical replication with slot, after changing
(increasing) the max_connections on the primary, I had this message at
a restart from the standby:

DETAIL:  max_connections = 100 is a lower setting than on the primary
server, where its value was 300.

and the standby does not start until I raise also its max_connections.
Why is PostgreSQL requiring the max_connections to be aligned between
the primary and the standby?

Thanks,
Luca