RV's and Motorhomes are not sold, serviced or warrantied like vehicles. Nothing in your experience with vehicles is directly comparable to how RV's are managed and serviced.
It is much closer to how a home is warrantied and serviced.
A motorhome has two separate systems warranty wise.
The chassis, motor, transmission and running gear are usually warrantied and serviced by the company which built them and sold a bare chassis to the motorhome manufacturer. You see a lot of motorhomes at Freightliner dealerships, service outlets. The motorized mechanical aspects of the motorhome are usually dealt with quicker, easier and more efficently and more cost effectively by a big truck dealer/ repair shop. They have mechanics trained to deal with those systems, and many do a good bit of RV business. Diesel pushers seem to have less issues dealing with the truck companies than gasoline powered Class A units which often have to find a Ford dealer who also works with heavy Ford trucks.
I've been to several dealerships which sell a lot of Class A units, both gas and diesel powered, who do not service any motor/ chassis related part of the rig beyond an oil change. And overpriced at that.
The 'coach' is warrantied by the company which build the coach - Monaco, Thor, Winnabago. However only the 'shell' of the body is warrantied by the manufacturer.
The fridge, the furnace, the water pump, the sink facuets, the AC's, the TV, the stove, the microwave, etc, - are all under their individual warranty from the company which built them and sold them to the coach manufacturer.
This is like a home where the home builder does not warranty the 'appliances'.
A good RV service facility does have people familiar with most of the major RV appliances and has relationships with the companies so that they can get parts and warranty work done if applicable.
A special note on tires - as mentioned above.
RV tires almost never need to be replaced due to tread wear. Forget everything you learned about tires for vehicles.
The vast majority of RV tires 'age out' not 'wear out'.
The main reason to watch tread wear on an RV is for overloading, under inflation, etc patterns of damage.
It is important to know when each of the tires was manufactured. I would not consider any RV tire over five years old 'safe' on the road.