Too many relations on a single object sometimes cause problems when editing large multipolygons (usually forests, meadows), in extreme cases where mapping is done only with relations (I hate this way because it complicates further edits terribly e.g. https://www.openstreetmap.org/relation/17155012 or https://www.openstreetmap.org/relation/5359731 ). Therefore, in my opinion it is good practice, if possible, to cut larger areas into smaller ones with future edits in mind, and to use relations themselves in moderation, like a condiment and not the main dish. I try if possible to avoid adding an excessive number of relationships.