IMHO, the answer is no. When a character starts adventuring, they are just starting at being an adventurer. They're learning how to fight off a monster and the various minions who work for a particular villain within the setting. They're going out into the wider world and they're interacting with other people in the outside world, some of whom they had only heard in stories the bards have told to them. But as they continue to adventure, they become stronger and more powerful. Leveling up in an RPG is the metric by which we, the player, know as to how powerful our characters have become. Without that metric, can we really tell where our characters are in terms of ability and power?
I disagree that you need to start adventuring, or at least start an RPG campaign, as a novice. You can, but you definitely don't have to. The hobbits in Lord of the Rings might be novices, but Aragorn, Legolas, Gimli, Boromir, and Gandalf certainly aren't. Amos Burton, Naomi Nagata, James Holden, Alex Kamal, and Roberta Draper certainly aren't the equivalent of 1st, or even 3rd, level characters when we first meet them. Xena has many skills, and a background as a warlord terrorizing nations. John Sheridan is a decorated war hero, and Delenn is secretly a member of the ruling council of the second most powerful (well, third) nation in known space.
That said, when we meet most of those, they're all coming into a new
context. The Fellowship is going on a quest to destroy the One Ring. The future crew of the
Rocinante are seeing their mothership the
Canterbury being destroyed, and themselves being drawn into interplanetary intrigue. Xena is leaving her warlording days behind her, and trying to be a hero instead. John Sheridan is being assigned command of a space station and start being not just a starship captain but also a diplomat. That's where the secret sauce is coming from: competent characters with a fair bit of (not necessarily detailed, but alluded to) background story coming into a new situation and seeing how things shake out.
And I think that works in RPGs too. While a lot of Critical Role's initial success can be attributed to Matt Mercer's DMing skill and world-building, and the players being what Matt Colville referred to as "professionally charming", I think part of it is that they had already been playing for a while. The PCs had established dynamics, and were starting at something like level 7. I wonder if maybe that's why I never could get into one of their subsequent campaigns, because they were starting at low level (2-3 IIRC) and having that awkward establishing stage, and that just didn't appeal to me.
I think danger is important. It doesn't require combat, but suspense, the threat of discovery and possibly combat, or just dangling off a cliff edge, that's integral. Discovering strange new places, yeah- and finding treasure.
Wow! So "Levelling Up" has 0 votes!
Now, I know its a 'pick one' vote... but really...?
Not one person thinks that levelling up and gaining appreciably more power is a main feature of "adventuring"?
Not of adventuring itself. It's something that might happen as a consequence of it, but "grinding XP" or the equivalent has never appealed to me.