If you don't have access to the nether at all, it's definitely much much harder, but if you have a void nether it's much more doable
Piglins spawn in their specific biome so long as there's a block for them to spawn on, so you can use bartering to get Nether Brick, Soul Sand, and Nether Quartz.
Blazes and Wither Skeletons will spawn within the bounding box of a fortress, even if there's no fortress there. Blaze rods can be converted into nether wart with the catalyst
A wandering trader can sell mushrooms of both varieties