The safety topic is such a muddy one with very strong opinions on either side – the responses range from polite to “wow, I can’t believe they said that”. So, which is safer? A truck pulling a trailer or a motorhome?
Most motorhomes aren’t crash tested but their seatbelt positions must pass FMVSS 209 certification. Here is a very common link that is shared that talks about the dangers of car seats in motorhomes. On the flip-side, here is a Facebook group of families who have decided it’s within their risk tolerance.
Trucks are crash tested but not with 5-20,000+ trailers mere feet from the rear seat.
At the end of the day, every family must decide where their comfort level is and proceed. Best wishes in your decision process.