They probably will eventually. But it’s early days so far. They do plan to send an orbiter and a lander. I’m not sure if it’s time yet to send a lander.

The problem is that we only have flyby photographs of Europa and they are only medium resolution. We could do with a much better understanding of it before sending anything to the surface.

As an example, what if much of the surface looks like this?

A rover or lander would run into serious trouble just landing there, never mind moving around. We don’t have high enough resolution photos yet to rule out something like this.

We also have the problem that it might have liquid water close to the surface, and whether or not, they think there are geological processes in the ice that take surface material and buries it into the oceans.

So then, if there’s a chance it can encounter liquid water - how do we sterilize it adequately to keep Earth life out of Europa’s ocean? We don’t yet have a way to sterilize spacecraft 100% though it is surely not impossible in theory.

The ideal way to study it’s oceans might be to fly through geysers - either natural ones which it might have but not certain if it does - or somehow to create an artificial one perhaps by impacting a sterilized “dumb” penetrator into the surface. That way we can collect the freshest possible samples, and do it without any significant risk of contaminating it with Earth microbes.

However by the time any orbiter gets there, perhaps by the 2020s, then we may well have the ability to build and launch a new orbiter, or lander or rover to get there in a much faster and shorter journey. So we might not lose a huge amount of time by focusing on the most capable possible orbiter for the first mission. I think that’s the priority myself, any extra mass you would put into a lander is best used to make the orbiter more capable - or perhaps to do a second orbiter mission to Saturn’s Enceladus. And then follow up with a lander depending on what you find. If you can make the lander 100% sterile, perhaps also miniaturized, then that would be ideal for planetary protection, give us another decade or two, and I think 100% sterile landers are maybe not totally impossible.

If we can’t land on Europa in a biologically reversible way, I think we should simply just postpone those landings until we can, and meanwhile study from orbit and flying through any plumes, artificial or natural. If we introduce Earth microbes to Europa irreversibly, that will affect not just us and our descendants but all future civilizations on Earth, as we’d no longer be able to study Europa as it was before the introduction of Earth life.

For more about this: Robert Walker's answer to If there is a possibility of life on Europa, then why did NASA land a craft on Titan and not Europa?