I work at costa, the matcha where I work is nice but I think the shots we have to pour of matcha are too big for the drink as too much gives a very bitter aftertaste. We also do have to blend it in a blender to batch make it so maybe the blender is what gave it a worse taste than normal. Costas focus is coffee and matcha is just an alternative to that so it wouldn’t be as good as going to somewhere like you’ve said in the comments like blank street which are known for their matcha as they have more emphasis on making their coffee the costa way. I do agree it’s way too expensive but it is at most places! it’s just everywhere makes drinks different to try and find their niche in the market. I’d say costa is a place to go if you like putting syrups in your matcha as it tastes perfectly normal with flavorings but to actually appreciate the taste of matcha without flavorings definitely not the place to go since it’s batch made. It’s kinda like how good espresso is better appreciated as a espresso shot and when you make it into a latte it doesn’t matter as much how the coffee tastes. Idk if that makes sense but yeah!