The Culture: Maybe Play A Game That Supports This Then?

The spirit is good here. The complaint is valid for games other than AD&D1e.

But, as usual, the problem is that the complaint presumes that a specific game doesn't already have this baked into its rules in some fashion.

This is the sort of complaint that applies to Palladium Fantasy and other such games that don't bother to make concrete in rules and procedures what takes to take down a dragon, so it feels like you're playing Shining Force and it's just animated GIFs flashing at each other until someone's HP total hits zero.

Compare that to a game that does. From AD&D1e's Monster Manual:

• Hit Point per Hit Die by Age Category (p. 29)
• Equal Day and Night vision (Infravision 60'); all senses excellent and thus can Detect Hidden or Invisible creatures at 1" (tabletop) per Category. (p. 30)
• At Adult and older, causes Fear when flying overhead or charges that auto-panics weak and non-predatory/non-wartrained creatures, forces saves against bigger ones, can inflict attack penalties on same until at 6+ Hit Dice/Levels, and it gets harder to resist the older they get. This is the legendary Dragon Fear. (ibid)

Read those pages carefully. They are very powerful advantages that all dragons enjoy; they are more potent with age and Intelligence (Ancient Red Dragons are terrifying inherently, before any specific items or magics any individual has). They are not immortal or invulnerable.

Yes, your armies are going to be scattered before them and your baggage trains reduced to fodder. You are not besieging the lair; you, at best, will encircle it and keep any minions from entering or leaving. The act of slaying is solely for proven heroes to even attempt. This is Working As Intended.

Those keen senses? They also open up attack vectors. Sudden and violent explosions of sound, light, or smell can (and should) force a dragon to pause just enough to grant the attacker necessary advantage to act. Elemental affinities suggest obvious hard counters. Knowing the psychological profile of any dragon suggests ways to manipulate it to your advantage. Consulting with a Sage can reveal these to those willing and able to pay the Sage's fees, if they cannot find this out themselves.

Yes, what DD wants is explicitly supported in AD&D1e- hard-coded, one might say. Just play games like that then; no point trying to fix a busted game when it's easier to get one that works.