Well, when the enemies don’t spot one of my characters, that character gets unlucky with initiative, and then takes an unwarranted hammering before I can bring the rest of my party in!
The issue with fixing this in the current system is that stealth players in the single player mode will get screwed if
all characters are forced to join the combat when one attacks. We would need them to add a proper pause function and ready attack before they even try to make everyone enter combat at the same time. Then those of us with multiple stealthy characters in the party can simply use TB with readied attacks and those who seem to have your issue would not have it.
Highlighted is exactly how combat
should work in D&D, and would fix this issue entirely.
The DM determines who might be surprised. If neither side tries to be stealthy, they automatically notice each other. Otherwise, the DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side. Any character or monster that doesn't notice a threat is surprised at the start of the encounter.
If you're surprised, you can't move or take an action on your first turn of the combat, and you can't take a reaction until that turn ends. A member of a group can be surprised even if the other members aren't.
If combat is initiated, EVERYONE rolls initiative and enters combat. Combatants who were unaware are Surprised and cannot act in the first round.
There's no need to have everyone Ready attacks before starting combat -> this is covered by the existence of the Surprised Condition (effectively giving the party a surprise round if the enemies fail their Perception checks).
If a single enemy finds a stealthed party member, then I'd argue that only that enemy is automatically aware of the party. Other nearby enemies would still need to succeed their Perception check or be Surprised, making it very unlikely that you'd have situation where every single enemy can attack that PC before that PC (or the rest of the party) gets a turn.