Safer sleep guidance says to be in the same room as your baby for naps until 6 months.
^^ This is why it's not done anymore. Lullaby Trust, NHS SIDS guidance et al say baby must be in same room as caregiver as it helps them to regulate their breathing and prevents them falling into too deep a sleep. These great long naps allegedly brought about by outdoor sleeping are not considered physiologically safe for the baby.
That said, in desperation, I did try outdoor naps a few times - made feck all difference to my sleep dodgers. To those of you who think yours slept longer at night because of outdoor naps - no. You just got lucky with natural sleepers.
I had no choice but to let mine nap on me - there was nowhere else they would for longer than 10 minutes. I'm glad some of you think this is some kind of indulgent luxury, but there was nowhere else mine would sleep or nap until well over a year old, despite all best efforts to convince them otherwise.