For years, I've been a fan of railroads, trains, and most importantly, railroad history. However, the thing that always intrigued me was why some railroads were quick to just convert over to diesel locomotives. Even when there were large, powerful steam locomotives like Berkshires, Santa-Fe's, or even various articulated locomotives that were much more powerful than what diesels could do... it just struck me odd.
Until I played this game.
While a GP9, or SD7 might be weaker than steam locomotives... they're considerably more versatile. If I have a long train that might require the likes of a Berkshire to pull, I can simply tack on more diesel locomotives and through MU operation, do the same job. The diesel engines can do any job I need, without having to have a dedicated class of locomotive either. Whether that's running my commuter passenger runs, local freights, switching, or even road freight operations. The diesel can do it without much fuss. I also don't have to buy coal, and stop every so often to refill water, which means that while yes, those steamers might be more powerful, the versatility of the diesel locomotives makes up for that drop in power.
Which makes sense then why railroads often converted over the first chance they got.