There may come a time in your campaign, where you as a GM may wish to introduce an NPC to the game that could guide the party along the story.
Much like a quest giver or a contact/source of information. Or even as a companion that could join the party on their quest and help out.
How subtle you are about these things, is entirely up to you.
In games, we often see waves upon waves of minions (or often called ‘Mooks’). Even in tabletop and roleplay or even movies, we see a lot of unimportant faces creating an obstacle for our heroes. At times though, we notice a few characters standing out above the rest (even if they are still minions at the end of the day). These individuals may be slightly taller, larger, don’t wear a helmet, have a name, or are equipped better than their standard rank and file allies. Here we could immediately recognize these individuals as not simply standing out in presence but also in ability when compared to their comrades.
These characters have a much bigger chance to be remembered, depending on just how memorable they were. How much they stood out.
Batman has the Batcave.
Superman has his fortress of solitude.
Deadpool has his appartment.
Wolverine has the X-men Mansion, despite roaming about and being a loner.
Robin hood has a glade in Sherwood forest.
Smaug ‘had’ Erebor. (Spoilers…)
Spawn has his alleyways.
Neo had that small ship in the first Matrix movie.
SG1 has the Cheyenne mountain complex.
The list goes on.
Regardless of your players wanting it or not (or even realize it), they will likely end up with a base of operations. A place to rest their heads and call home. To sell their loot and buy their gear. Where they can gather information for their next mission, and store their hard earned currency etc. If only temporarily, before moving on to the next.
This could be anything from your typical inn or tavern, a district or even an entire city. A flying airship, an airplane or a star ship. A mansion, a castle, the local YMCA or their employers Volcanic Lair. (See Evil villain, fire lord or Red Dragon)
Hell, it could even be the RV from Breaking Bad.