things i noticed you did wrong:
you got scared as hell off stage when you waited too long to recover and died twice as a result, after that you tried to recover too early and forget to throw out Necessary up-airs for recovery, you just wave to learn to recognize the situations you can and can't tether
you go too hard to combo, i noticed a couple time times you would take to the air against this ike, and then if you missed your follow up, you would be in a bad position because ike would have landed and you would be right above him. Generally, i find it better to wait on the ground for follow ups, and use jumps to bait airdodges, or jump low enough that even if i miss, i can land and pivot grab or upsmash. But i NEVER try to go hard on follow ups UNLESS i have a good read or know i can frame trap with upair (gets airdodged) to a fair
you throw side-B too much. Odd as it sounds, i don't throw side-B unless they are in the air NOT approaching into an attack spacing, or unless they are far enough then i can shorthop side-b and then land to pivot grab before they can reach me. only exception is when i have purple, which i chuck in any situation where it can hit or force a defensive reaction. Also, if you see him trying to stop side-b with attacks, that a free punish. The reason im saying this is because i noticed a few times you used side-b when the ike was in range, and then he landed a fair or something, which pretty much screwed you over.
Space more. PLEASE, TRY TO ALWAYS STAY WITHIN OLIMAR OPTIMAL RANGE, RIGHT OUTSIDE HIS GRAB/FSMASH RANGE. Its a pet peeve of mine when olimar's get out of their spacing and don't make any attempt to get back into spacing instantly, i noticed you stopped this the more the matches went on, but it should be something you don't even have to worry about.
Your OOS game isn't too good, you did shield grabs at the wrong time, did not use JC US OOS, didn't roll away or spotdodge OOS, you could of also waited in the shield until an opening was made by him attacking, or heck, even getting grabbed wouldn't be the worst thing compared todropping shield and getting faired or jabbed.
I don't see much use of specific pikmin colors, i try to use each pikmin the best based on their color, like abuse yellow priority, white's pummel damage, red's amazing aerials and favorable trades, ect. i feel like you just throw out all your attacks without considering pikmin too much
punish landings, quite simply, you never put yourself in a position to punish a landing
This is more of a playstyle technique then anything, but your attacks should create a wall of hitboxes and grab boxes, i didn't you utilizing the defensive but offensive pressure olimar can use, mainly because you don't play fast
I realize that you don't know how to play the MU, but those are the fundamentals you should work on. Your not bad at all honestly, you did good considering red-X actually knows a bit about the MU from me. BTW, you have AMAZING timing when it comes to spotdodges, i was actually impressed with the things you managed to spotdodge and punish.