You could argue the same for most games on most Engines. Half Life: Alyx is the same engine as half-life 2 with more shit added over the years (I think they’ve changed it with the upgrade to Source 2, but this really showed as all Valve games would run as hl2.exe, and source 2 is merely an evolution, not a rewrite).

However Bethesda’s Creative Engine was already quite dated by the time Skyrim came out 12 years ago, and hasn’t received any meaningful improvements since. Honestly at this point it’s not a technical issue, any competent software team could have incrementally fixed and upgraded the engine over 12 years, no matter how buggy it was when Skyrim was released and how much spaghetti there was to clean up.
Bethesda just doesn’t care that their game mechanics are stuck in 2009 and the management is probably too set in its ways to figure out another way to write quests or design level without loading screens, too comfortable with the ease of writing dialogue trees without mocap or even some basic “first year of film school” camera placement.

Too bad for them Baldur’s Gate 3 showed the world that these things actually matter. I won’t hold my breath for TES VI, the technical gap on their engine is only growing and they still haven’t indicated even an acknowledgement of its flaws.