I can't say I blame you as he hasn't really ever been a consistent starter, however, he has been at two of the biggest clubs in world football and there's no shame in that.
He brings all the things Lukaku brings the table, strong, great in the air, quick and can spearhead counters, can hold it up and is a very good finisher. He has better technique than Lukaku and also works harder off the ball, I think he has a higher ceiling overall.
Lukaku though has been pretty damn good this season, has the consistent record and all of his goals were from open play with a good mixture from the left foot, right foot and headers which is very impressive. Looks like he's definitely ready for a big move and I'd be happy with either but as you said I doubt Lukaku will be too happy about missing out on CL football whereas Morata most likely wouldn't mind initially.
City are just getting started and we're most likely going to get left behind particularly without making big boy signings.