Rogues cannot actually hide where there is no place to hide. They need to also have invisibility. Something as simple as a brightly lit open area prevents that. When they hide it doesn't mean the heavy armor low dex cleric doesn't blow it for the group anyway.
At one point it was mentioned games would be playable without proficiency or with optional proficiency rules. The basic assumption was the ability check was the basic mechanic and that's what most monsters use. Anything beyond a standard ability check is above and beyond the expected standard.
It's generally no bonus is 50% success vs easy, 25% vs moderate, almost impossible vs hard, out of reach for very hard or near impossible tasks. That's increased with a combination of natural skill or training (proficiency) so a +5 bonus (either some skill and natural ability at lower levels, high talent or natural abilities at high levels) allows for 75% success vs easy, 50% vs moderate, 25% vs hard, almost impossible for very hard, out of reach for nearly impossible. Assuming a check is required, OC.
That's where most characters fall into place. A perception proficiency and high wisdom score isn't normal to start with. Perception isn't on the proficiency lists available to clerics and monks, and clerics don't normally take a background to add it. Monks might but monks and druids are the two class who combine both wisdom and proficiency, and they are rare classes. An example that doesn't typically exist isn't really indicative of what's happening. If it were, more players would be plaything those two classes.
Expertise is possible but that doesn't usually coincide with high wisdom because of ability score competition.
Low level monsters don't scale as well as combat against PC's so I'm not sure where the expectation that they would in skills. However, it's possible for numbers to apply advantage or disadvantage to NPC's / PC's as applicable via helping / hindering, and NPC's can also take advantage of the "take 20" spending extra time in prep while there's no inherent danger or distraction. Kobold trapsmith's concealing a trap, for example.
I would say a high level fighter isn't going to struggle with grappling an ogre. The fighter's strength, training, and experience are going to be too much. Two ogres grappling a high level wizard aren't going to struggle in the slightest. Examine what intelligent (or at least semi-intelligent) monsters are actually doing. Comparing poor score against the best scores doesn't tell the full story,
Ultimately, if the DM wants the monster to demonstrate training beyond what's typical of the monster's race or characteristics then give it proficiency. If the DM wants the monster to demonstrate experience beyond what's typical give it proficiency and increase it's HD, or give it actual class levels.
It's only an issue if someone assumes it's not working as intended. It takes uncommon combinations to get some of the highest bonuses being discussed. PC's aren't going to have proficiency plus high ability scores in most of the checks to be made for any given character due to limited numbers of proficiencies and ASI's.