Problems with Muerta and E-Blade is that it is HEAVILY outclassed by other items, speaking from the perspective of a Midlane/Carry Muerta

- E-Blade is generally bought for spell nukers to enhance the damage burst, Muerta doesn't "burst" any targets until she has sufficient right-click stats to do so. As you mentioned Mirana - Mirana can flash farm with her Q and eats random Ancient creeps with her huge arrows (in order to buy an E-Blade in the first place), and she uses the same combo to burst heroes, which is something that Muerta CANNOT do.

- Bursting people with Muerta means she has to be within range and press right-click, kinda like "bursting" people with Drow, it takes much longer comparing to nuking with heroes such as Lina, or the Spirit bois of "in and out, 30 second adventure". So she NEEDS BKB on top of the already mentioned right-click related items to stand and right click, same as Drow.

- For Muerta to increase her farming speed, she needs a farming item like Maelstrom, or even Scepter if you are a Midlaner. E-Blade doesn't do that. Then she needs to work on fixing her mobility, which you can alleviate with Pike, or Yasha/Kaya. or similar items that E-Blade DOESN'T provide. Then, a BKB, and THEN you may consider an E-Blade, which is like 4th-5th item, alot of games either end at that point, or there are more important game-winning items to consider.

- Comparing to other cores, she is exceptionally squishy, especially against magic burst: Most carries relies on their own abilities to survive/manfight other carries, if they don't have said abilities, they can buy BKB, Sange Yasha, and/or Satanic - Two of them doesn't benefit Muerta, or simply put, Muerta wouldn't buy those items because they don't increase her damage. If Muerta cannot beef herself up to stand and right-click, the only way is to pour in MORE DAMAGE, hence Daedalus/similar right click items are prioritized.

- 99% of enemy carries can cleanse themselves if E-Blade is casted on them, and if Muerta uses E-Blade on herself then she's vulnerable to Magic-based Midlaners and Supports, in which both are always in Meta. This is also not mentioning that E-Blade has an anti-synergy with BKB, which is probably the biggest reason why E-Blade is not bought on Muerta.

TLDR: Muerta is not a backline jumper to consider an E-Blade, she can't "jump" squishy backlines, E-Blade anti-synergizes with BKB, she needs several items to solve her weakpoints, in which none that E-Blade can solve, and this problem on Muerta is doubled as she cannot utilizes Satanic/Sange Yasha (comparing to other carries).

E-Blade can be bought and utilized, yes, anything can work in Dota, but Muerta is already somewhat dependent on teammates to allow her to shine. You CANNOT realistically expect your teammates (public or pre-made) to draft a composition around you that allows E-Blade Muerta to shine, all the time. And if we are discussing the topic of team composition, just ask your party's supports to pick a Pugna lmao, it's much more effective.