Deck variance, in general, is a large reason that I have strongly favored Dredge, and what pushes a lot of players away from the game. It feels fair/fun to me to lose to your own decision making process, and your own decisions. It feels less fair/fun to me to lose simply to the game's shuffling and mulligan mechanics. I was excited to have some more options, outside of Dredge, that could give a more consistent game experience. Alas, it looks like they are now unlikely to support such a concept in Vintage/Legacy moving forward.
Variance has a lot of levels within its range. Too much variance and the game is unfun because you have little control over what happens, you're at the whim of fate. This is the primary complain of people who play Hearthstone, where there are cards that have randomness built into them to a sometimes silly degree. Too little variance and it turns closer and closer into chess or checkers, where the way games play out is always similar. There has always been a tension about how much variance is too much or too little, as well as how to actually get us into the proper range since card design is an imperfect science.
If you look at the moves WOTC has been making over the past few years, if not a great many years, it has been to reduce variance. They have consistently felt that variance, and very specifically opening hand variance and the variance the mana system provides, was detrimental to the game. All of the following things WOTC has done has reduced variance:
- 2-3 sets of new Mulligan rules
- Making Scry an evergreen mechanic
- Revisiting cycling several times and pushing it every time. Take a look at the cycling deck in standard right now for a good example, it's literally using a number of cards it cannot ever cast just to cycle.
- The printing of enemy color fetch lands in Zendikar
- The general push in the utility of mana producing cards (shy of reprinting true duals, which they cannot). In addition to shocks we now have Fast lands, Check lands, etc, which are all just adding power and redundancy to decks.
- The power creep in new cards, which has overall equated to generally lower CMCs for normally more expensive effects. Gitaxian probe vs. Peek for instance, or just Oko and 3 CMC Teferi vs every other walker ever.
- The active planting of specific cards into sets to help steer formats where they want (Modern Horizons)
- The constant return to Free, alternate casting cost spells and the glorious way they screw the pooch and make them too good every single time (Hogaak, Once upon a time, Force of Vigor)
The addition of companion, which was intended to have a real cost to play in its requirements, is scarcely the thing that is causing a lack of variance. Honestly most companions don't even come on line until much of the game has grinded out and none of them help you if you stumble early with bad mana or excessive mulligans, which is not so much a feature of vintage because of all the other steps WOTC has taken which I listed above.