I rented a crappy mtb in Siena Italy and brought my own pedals, shoes, and helmet. it is hard to rent a road bike. Without realizing it (ha) we did one of the climbs on the Giro on those crappy bikes. Even my husband had to stop.
On the bike tours I've been on, everyone brings their own seat, and anyone who uses clipless brings shoes and pedals. A few used the groups's helmet, but most brought their own.