Just check on the internet. Some players are soloing act 1 with no issue whatsoever.
They are using exploit and meta-knowledge to do that. Everyone can solo Act 1 with barrel cheese and abusing surface in general. Everyone can abuse shove. Everyone can summon the Imp familiar with good attack and bonus action invisibility on demand or the spider familiar with 33 hp too. Or abuse the stealth mechanic which is entirely line of sight based so as long as you aren't in the red cone you don't even need to be good at sneaking.
Nobody can solo the spider Matriarch with 0 prior knowledge. She can one-shot a level 4 character with her range attack and you'll trigger the fight before you see her unless you stealth rolls are good...and you can't one-shot her with stealth attacks with her amount of HP. She's only worth 20 XP, killing level 3 goblins is more rewarding too...
You can also do the entire critical path (i.e. get to the boat in the Underdark) by fighting exactly 0 enemies outside maybe a Bulette encounter where she runs away after a round. Doesn't require stealth, just abusing the tadpole conversation. I've done it yesterday, but took the time to kill the 3 leaders because why not.
People are right in saying the game isn't hard despite the HP bloat, even without all the cheese, but the reasons for that are:
1. the AI taking dumb decisions (focusing on downed party members...lol).
2. Long resting after every after fight, which appears to be a design decision with how camp conversations triggers.
3. The amount of scrolls, magical arrows, magical items you can find and the fact that everyone can cast spells from scrolls. A level 5 character in a high magic setting in 5e should only have 1 uncommon magical item. You get enough to fill all equipment slots in the EA except cloak as there are no cloak.
4. Meta-knowledge, going blindly into a fight is different than doing it for a second time.
1. Can be improve in development.
2. This really need to be reworked. You shouldn't be able to go the camp when there are potential enemies nearby.
3. That one is not going to change, as video gamers need their sparkling equipment and they need it fast otherwise they get bored.
4. Not something the devs can fix really.
