How would you want ES6 guild questlines to end?

This has been bothering me for quite some time, I was thinking about the guilds in Oblivion and Skyrim and how at the end of each guild questline, the game just makes you the guild leader? And even for guilds with different mottos.
Example :
You can become the guild master of the Fighter's guild AND the thieves guild AND the Dark Brotherhood all at the same time.
The problem with this is that the Fighter's guild brandishes themselves as a noble group, a group that does extensive background checks, no murderers, no thieves, that sort of stuff. This makes it weird that a member of thieves guild or dark brotherhood would want to be part of the Fighter's guild and let alone the guild would make them their master. Does no one from the Fighter's guild see the player enter Cheydinhal's abandoned house? Or does no one notice the player go to Othrelo's house? or meet up with shady characters and ask about it? Idk about others, but this makes the world feels so shallow and unlived.
Additionally, after you become guild masters, the questline ends. You can't guide the guild anywhere or anything, you're just there.

This just pisses me off so much. Would you like TES6 to have similar inconsequential endings? and all guilds being open to the player regardless of previous choices? Or do you want something else like me?