Low humidity
Indoor air, especially in winter with heating on, often sits below 30% relative humidity, and tropical species evolved for 60%+ struggle to keep their leaf edges alive. The damage is cosmetic at first and progressive if unchanged.
Based on what you've described, these are the likeliest causes — ranked. Each one carries a tell-tale sign that distinguishes it from the others, and a single-minute check to confirm.
Indoor air, especially in winter with heating on, often sits below 30% relative humidity, and tropical species evolved for 60%+ struggle to keep their leaf edges alive. The damage is cosmetic at first and progressive if unchanged.
The plant has been dry for long enough that cells have lost turgor and leaf tissue is starting to die back at the margins. Drought-tolerant species forgive this; thirsty species like peace lily or fiddle leaf fig do not.
Over months of feeding, mineral salts from fertilizer and hard tap water accumulate in the soil and on the pot rim, burning root tips and pulling moisture out of roots through osmosis. It masquerades as underwatering because the symptoms overlap almost exactly.
brown-leaf-edges--brown-leaf-tips