I really like the 1.19 update and my favorite feature is the ancient city from adventures ,lore to building places and maps it has everything but I hate activating cheats or searching hours on end without finding one so I would suggest a map like the treasure map wich you could maybe find in certaint structures wich would fit in the lore with the chance getting higher with the rarity of the structures for example: in a village in a common chest a 1/1000 chance and in a end_city a 1/30 chance I know this has been probably already suggested but maybe this will get the attention from someone at mojang who will put an idea for an easier way to find an ancient_city under review
Mojang doesn't visit/look at this site, it's primarily for fans.
They probably didn't implement a more sure method of locating ancient cities because it's intended to be a rare find. There is the theoretical method of checking under mountain biomes (not guaranteed, but may be more likely to spawn under them), or just strip-mining at the general level they always spawn on. Otherwise, there might be mods involving maps or finders to them, or seed map websites that show their locations.