Maybe it's a bit of a reductionist view, but at a larger timeframe, eternal formats don't really exist. They thrive for a time and are then replaced by something else. Legacy replaced Vintage, Modern replaced Legacy, one day Pioneer will replace Modern and after that, new formats will be born. Yes, there are still Vintage and Legacy players, but at a macro scale, the percentage of players is shrinking.
I think it is very okay to accept this as a fact of the game.

The word “eternal” is a poor choice as we use “eternal” to mean formats with access to (mostly) all the cards. Vintage, Legacy, and Commander are all eternal formats. So eternal formats do exist. : )But your larger point of how Magic keeps shifting where it focuses its formats is true.

Set B "obsoletes" set A is a strong word, but let's focus a moment on pioneer, not very old vintage cards. I have a database of "top playables" in pioneer, restarted after every banning. Cards get into list based on certain number of appearances in goldfish's tournament winners, but criteria is equal to all cards. 9 OG Theros cards are on the list, 5 KTK cards. 4 RTR cards (+ shocks) 21 MKM cards are. 20 LCI cards. 13 OTJ. New sets have vastly more cards in list, thus are stronger.

The switch for a Standard-focus to an Eternal-focus forced us to up the overall power level of premier sets in Throne of Eldraine, so yes, Throne of Eldraine and sets after do have an overall high power level. That wasn’t set by set creep though, but a conscious one-time adjustment.

Can you elaborate on why you can't make commander-only cards? While Wizards doesn't have explicit control over Commander legality, it seems like you ought to have de facto control by virtue of the fact that you can dictate legality for most non-commander formats.If, for example, you had pre-emptively banned sticker cards from Legacy and Vintage, the end result would be that the cards would be only legal in Commander and Limited. Is there a reason you don't consider doing something like that a viable option?

We don’t like pre-banning cards. It also just adds a lot of card names to the banned list which makes it harder to process.Commander is in an odd place as there’s a separate group that determines legality. We’re trying to not overstep our bounds.

Can’t Wizards automatically ban cards in legacy, vintage, pauper, etc. as a work around to have the cards not effect tournament formats but be legal in Commander?

It’s not something we normally do. We ban cards when they cause a problem, not because they potentially could.

Do you think MTGO could handle Clocknapper? (Unstable card that lets you steal one part of your opponents turn). It's a paper Vintage Cube powerhouse that I think deserves a spot in the MTGO cube.

MTGO usually requires the cards to work within the rules which Clocknapper does not.

When LSV recently did a top 50 vintage cube list, the #11 slot was Minsc and Boo, the first card on the list not from Alpha. Vintage cube red has gone from being one drop based to 3 and 4 drop based - because the power level of modern 3 and 4 cost cards is so high. Jace the Mind Sculptor is now an upper medium power planeswalker, not the ceiling. Is this not power creep?

Power creep isn’t about us making individually strong cards. It’s us making whole sets where the overall power level is higher than all the sets that came before it.

In the interest of Wotc playing attention to non-commander formats, has there ever been talk of taking away format staples for a brief period of time? As long its communucated effectively that the cards are not banned forever I'd like to see what legacy looks like without Daze for like 3 months, or modern without Force of Negation for a season or so. I like that vintage saw the unrestriction of Ponder as a way to shake up the format, and want that for other formats as well.

I have pitched the idea of a “penalty box” where cards get sidelined for a specific amount of time, but it’s never gained traction.

If/when: cards like Seven Dwarves ("a deck can have up to N cards named X"), but N is fewer than 4

If. It’s a nerf in non-singleton formats , and we tend to avoid restricting things outside of Vintage.

Hi Mark! Magic has had cards that allow players to ignore the 4x (or 1x in Commander) limit on card copies in deckbuilding, and Magic has had post-printing restrictions on how many of a certain card you can take in your deck within specific formats. If or when: a card that is printed with the restriction of only being able to include one (or some other number less than the usual 4) of it in your deck.

The reason we avoid doing restricted lists in anything but Vintage is it raises the variance e higher than we like. So I’m skeptical we’ll do that.

Is it possible we could one day see a Legacy/Vintage Horizons product?

The audience for Legacy/Vintage sadly isn’t big enough to warrant such a product (in tabletop, at least).