This legitimately made me sad when I heard they might lose this satellite. It's the farthest humans have ever sent anything beyond Earth, and it might always be the case. The science data coming back from this is invaluable.
We'll surely get faster. Remember that Voyager 1 actually made a pass around one of the planets (Jupiter?) specifically to slow it down so that it could start gathering data. It would not be (relatively speaking) hard to send something out at a far greater velocity.
I'm glad they do, a lot of the missions I work around have been flying for 20 years when their original mission duration was supposed to be 5 years. The science they do is fantastic.
We can absolutely go way faster. The fastest thing we've ever built is currently the parker solar probe. Relative to the sun, it's traveling so fast it could do a flyby of earths entire width in (I'm just guessing, don't quote me) probably a couple seconds.
I just did the math. Parker's top speed is around 430,000mph. So with the earth being a bit over 7900 miles across it would take a minute for Parker to traverse the width of the earth.