No more Detect Good. Detect Holy instead.

[Vahnavoi]

Man is there a lot to unpack there. I realize you are replying to hamisphence, not me, but at this point hamisphence needs all help they can get.

And?
If a player has a clear concept for a cleric in mind, why would they ever need to change?

D&D is a dynamic game where what happens to your character is meant to be decided through your actions in the game. Approaching it with the mentality that your character is governed by an unchanging high concept, is an user error so severe, it escapes the rule set entirely. It is like choosing to play a strong character, while failing to acknowledge that there are diseases and curses which could make your character temporarily or permanently weak.

This said, Alignment doesn't exist to punish pious clerics. More on this below.

Its pointless. you choose a god made up or not, and just follow their beliefs, its a character with a lot of work already done for you, but without any actual restriction on what can be done with that character, because you've already decided what you want to do with them.

Playing according normal rules, a player cannot decide beforehand everything they want to do, because they do not know everything that can or will happen in the game. If you ever manage to preplay your character to that extent, you are not approaching the game like a normal player, you are approaching it as a robot executing preprogrammed algorithm. Why even play at that point, when you know everything that can happen?

any story involving a cleric losing and regaining their gods favor or changing to a different one would just negatively impact group effectiveness without any real consequence other than annoying other players. while any story of converting from one god to another like evil one to a good one can be left to an interesting backstory

The statement that "Alignment exists to facilitate a trope" (etc.) does not mean that trope is prescribed to happen in every game, for every game. "Negatively impacting group effectiveness" isn't even a consideration at this level; you might as well be worrying about a character dying. It's a possibility, not an eventuality.

now sure a GM could keep track of the clerics alignment and tenets and try to get rid of their powers when they start developing their character a certain way or when they fail to do something their god expects them to, but there are so many gods with so many different tenets and practices I honestly wouldn't expect a GM to remember them all amid so many other details of a world.

So you're assuming the GM won't be able to do the exact thing the rules say is the GM's job? This is the most blatant bad faith argument I've seen yet.

Furthermore a player would be more likely to keep track of the tenets and stick to them rigidly because its the character they want to play....and thus the stick of alignment is meaningless, because most players if they want to play such a concept wouldn't really care about changing deities midway through anyways- the spell list will be for the most part the same and if they wanted to play something else, they would've chosen that instead.

The "stick" of Alignment does not exist to punish pious clerics, nor players who are honestly interested in playing a pious clerics.

It exists for players who want to play through the redemption story. The sort who sees the "stick" and goes "Ooh! Kinky!" and then deliberately trigger the mechanics in an equivalent of screaming "Punish me harder, Daddy!" at the GM.

It exists for player who, during play, find themselves unable or unwilling to continue following their original pledge for their character, as a model of how losing divine favor and switching deities might work in a game.

It exists for players who don't keep track of and stick to tenets of their character's faith, because they only wanted mechanical power, and need the GM to remind them that those mechanical powers came with strings attached in the setting.

thus assuming no one is a jerk, the path of least narrative resistance unfolds: the GM not planning his campaign around whether or not a player loses his powers and the player not planning to lose his powers, the GM just describes the cleric slowly becoming their gods most favored worshipper or whatever and the character just ends up becoming a high priest of their religion because that is the safest option that doesn't get arguments over morality or complicated changes to one's character sheet.

Yes, that is what happens when a player succesfully plays a pious cleric. "Narrative resistance" doesn't enter to it. You are just assuming the cleric overcomes all of it. That's not something that can be decided "well in advance" ; even if the cleric never sways from their faith, they might get eaten by grue due to a mistake unrelated to their faith.