TL;DR: Yes, but only situationally. If you have access to green, play a fast deck, and/or have a commander that costs 3 or less, it's probably not in your best interest to run them.
I'll echo what everyone else has said in that it depends on how many colors you run in the deck, but what I'm seeing overlooked is that it depends on the CMC of your commander and how fast the deck is. For example, if your commander has a high CMC - say five or more - then I'd
consider running some regardless of how many colors the deck is - especially in decks that don't have green and consequently have fewer reliable ramp sources. However, if your commander costs three or less, I probably wouldn't run them. Ideally if your commander costs three, you're tyring to consistently cast it on turn three and not a 3-cost rock. If your commander costs 1 or 2 and you're casting a rock turn three instead of spells that further your gameplan (or at least cheaper/more efficient ramp), you're already falling behind. Even in a four or five-color deck, I'd sooner run things like
Fellwar Stone or
Ornithopter of Paradise than a
Commander's Sphere. If that's not enough, I'd still look at the Talismans first. In my Breya deck, my mana cost distribution is 45% blue spells with none of the other colors being higher than 21%. I just run the three Talismans that produce blue and one of my other colors instead of running 3-cost rocks.
Chromatic Lantern is probably the most worthwile 3-mana rock to run since it perfectly fixes all your colors and can itself tap for one mana of any color, but only in non-green three-color decks and four or five-color decks. I think
Coalition Relic is grossly underrated in this category, as it can get you two additional mana of any color the turn after you cast it as opposed to only one (tap for a
charge counter, untap at beginning of next turn, then tap for another
charge counter prior to precombat main phase).
Skyclave Relic is a strictly better
Darksteel Ingot because it has the kicker option. These three are really the only ones I'd
consider using universally (and yes,
Commander's Sphere is not in that list). There are others that are useful, but only in certain decks (i.e.
Altar of the Lost in Flashback decks,
Basalt Monolith as a combo piece,
Dragon's Hoard in Dragon tribal decks,
Elementalist's Palette in X-spell decks,
Strixhaven Stadium in go-wide combat-focused decks, etc.).