Bayonets were considered mostly as decorative items already back then. They were used in parades but the experience had shown that they had hardly any practical use in the battlefield. The light infantry had to move fast through rough terrains and sooner or later the infantrymen dumped all dead weight including gas-masks, bayonets and even steel helmets.
Hand-to-hand combats took place usually in trenches. Those combats were won by using hand grenades and Suomi SMG’s. If the enemy got really close, puukko was used. Anyway, in trenches or inside buildings a rifle with a bayonet is not too practical weapon as there’s no room to use it.
Some words about puukko: The puukko is one of the oldest multi-purpose tools mankind knows. It is 95% tool and only 5% weapon. This is why it looks a bit modest when compared with Rambo inspired tactical combat knives, which I myself find useful only as a poor substitute of a crowbar. Or as a bottom weight of a fishnet.
Puukko is one of those words that is very Finnish and quite difficult to translate, just like sauna or sisu. The artefact it describes belongs to the great family of knives and sharp weapons, but forms a sub-category all its own. It is the name given to a utensil that is used as a tool for all kinds of carving, and especially to work wood. Like a dagger, a puukko can serve as a weapon, but a dagger it is not. Neither is a small puukko a penknife, even though it is ideal for sharpening a pencil. Hunters and anglers can use a puukko to clean their catches, but a puukko is far more than just a hunting or fisherman's knife. It is a puukko.
As every soldier had his personal puukko with him (puukko is a very personal thing), no wonder that they got rid of their bayonets in the first possible occasion.