In the context of boring/stable, Starcraft 1 is a particularly interesting example. Most live-service competitive games rely on regular balance patches to "keep the meta from going stale", which has some parallels to the shiny-affinity of modern tech stacks. Starcraft 1 on the other hand have not had any changes to the balance in 20 years, yet the meta is still constantly evolving because it is emergent on player skill development instead of prescribed by hamfisted developer oversight.
I think that's the biggest difference between SC 1&2, although the former is still being nudged a bit through map design.
SC2 in its first decade has been about always keeping the game fresh - new units, new spells, adventurous changes, crazy maps. As of 2020, the changes not only stopped, but the game was caught for a few years in a pretty crappy state: nigh unbeatable PvT cheeses, 40min-long PvZs where Zerg is clearly winning but can't close the game, meanwhile no Protoss in top 10 GM or major tourney semifinals. The worst of it has now been fixed, but the changes are only slight tweaks and nudges, now again reminding me of Brood War. It's still an excellent game though.
