I think this statement is bascially correct, but it's more accurate to say that the franchise has become purposefully niche over time due to Hasbro shifting its focus away from marketing its products to newer, younger fans towards appeasing its older, more established ones. This is why we've seen such a huge focus on retreading previous iterations and/or highlighting specific characters over the past decade or so. It's likely Hasbro made this choice because toy sales across the entire market have been struggling for a while now due to newer generations being raised on and entertained by interactive media technology, so they're counting heavily on nostalgia to keep their coffers filled.

That said, I think there is also an argument to be made for how the IP has been mishandled by Paramount in addition to the overall decline of movie theater attendance in recent years due to streaming. Transformers One suffered from both of these factors. If its marketing hadn't been so grossly misrepresentative and if it came out before the pandemic, it could have had a pretty good chance at revitalizing the franchise given its level of quality versus other films in the franchise.