While reading through some of the comments some thoughts came to mind:
-I don't think DISCO jumping to the future is playing it safe. I think it's the opposite. I think trying to squeeze the series right before TOS was far safer (as was making Burnham Spock's sister, the very design of the Starship Discovery, doing a war with the Klingons, returning to the Mirror Universe, and even in season 2 with Pike, Spock, and Number One as well as bringing in Section 31. These were all things I think CBS thought would endear older fans to the series). If they had done a future series from jump it would've required a lot more world building and potentially even more expensive sets and effects as they had to create cool looking future technology. Even if we had started off with the series in the 32rd century I imagine there would've been concerns that veteran fans would not be as enthused to see the "Emerald Chain" as opposed to the familiar Klingons as the enemy.
-I think it's complicated to say that old fans don't want something new or different. Many old fans are often expressing that view, but of course it means different things for different people, and sometimes you don't know you wanted or will like something until you do. So to me it comes down to execution. The concept of a junior officer being the main character was different but I don't think the writing, the weight of the franchises' history which put the captain characters first, and that expectation from many fans, allowed the idea to really catch on in the way CBS hoped IMO. I have long felt that Burnham, on another series, would've been a potential breakout outsider character (Spock, Worf, Data, Odo, Seven, The Doctor, T'Pol, even Trip, etc.) and they didn't know how to realize that so they pretty much turned her into a captain-character almost right off the bat. Now I do think they've done a good job in fleshing out Burnham and giving her character and arc and a journey, so that's been successful, even if a bit awkwardly executed at times. The downside is that Trek fandom, and arguably other genre fandoms, have grown used to space opera ensembles (Star Wars, The Expanse, Babylon 5, Andromeda, Firefly, Stargate SG-1, you name it), and they've been less successful keeping the series revolving around Burnham while giving the other characters development. It's gotten better each season, but still needs a lot of work. And the nature of the storytelling for CBS Trek, with the one or two big stories a season put plot over character which further crimps their ability or space to develop an ensemble. Comparatively, the older Trek series all had longer seasons which allowed them to dedicate an episode or two to almost every main cast member every season. DISCO and PIC don't have that luxury. Instead they've banked on Burnham being such a dynamic character, rooted deep in Trek's history, and Picard, well, being Picard, to sell their respective series, come what may. I think Lower Decks has done a much better job building an ensemble series, but then again, that might have been the intention from the start as opposed to what DISCO and PIC intended.
-Another thing I was thinking about was the idea that other series are taking risks that Trek isn't or out-Trekking Trek, and I think about how series like Farscape and The Expanse are popular, among sci-fi fans, but do they have the reach or longevity of Star Trek? Even though I think Farscape and The Expanse are sometimes better written than DISCO and PIC, but not better made than DISCO, Star Trek (no matter the franchise entry) is still a much bigger, more popular brand. Granted, I don't know if the average person would know Burnham from James Holden, but they might be more familiar with the trappings of DISCO than they would any other sci-fi series except Star Wars. I would also contend that DISCO has taken some risks. It was risky to do a series only 10 years before TOS, to give Spock a sister we had never heard of, and a war with the Klingons we hadn't heard of either, and to visually make everything look so different (and I'm thinking risky in terms of getting old Trek fans on board), and it's also risky to jump to the future (more from a creative and budgetary standpoint), but I can't blame them for seemingly listening to some fan complaints and trying to create a series that will be as entertaining as they can make it.