Greek scholarship is doing a better job these days at reading larger units of text and looking for more macro patterns rather than just looking at individual words or phrases.
One of the patterns that has emerged in reading historical narrative material is that the aorist is the default tense, used to begin the narrative. Then, the imperfect is inserted in appropriate places to move the story along. This means that there is something explicitly significant about the tense change, and that emphasis should (I think) be explicit in translations.
"After this, Jesus and his disciples went (ἦλθεν) to the Judean countryside, where he spent (διέτριβεν) time with them and baptized (ἐβάπτιζεν)" (CSB, see also NIV). The narrative begins with an aorist and is followed by two imperfects, although the later two verbs are not translated as imperfective in aspect by the CSB and NIV. (I know, the "imperfect tense" and "imperfective aspect" can be confusing terminology, but these are the terms linguists are settling on.)
διέτριβεν is imperfect, but the simple "spent" is imperfective in meaning, so probably "was spending" is unnecessary (although I would vote for the later).
However, ἐβάπτιζεν is also imperfective, and it is not clear to me why the CSB and NIV do not translate it as such. They may have felt that the simple "baptized" was sufficiently imperfective (just like "spent"), or they may have preferred the simple form on literary grounds.
The problem is that it is under-translating, not getting all of the information out of the Greek (which is common and often necessary), but it also misses the larger contrast the text is creating. Vv 22-23 are contrasting the activities of Jesus and John. Jesus went (aorist) out into the country side, spending time (imperfective) with his disciples and baptizing (imperfective). "John also was baptizing (ἦν … βαπτίζων) in Aenon near Salim, because there was plenty of water there. People were coming (παρεγίνοντο) and being baptized (ἐβαπτίζοντο)" (CSB). It is not clear to me why you would translate the imperfects in v 23 but not in v 22. The NIV has the same oddity.
The larger question could be to ask how English tells narrative material. I don't think it is as important to us to start with the simple past and use the continuous past in the midst of the story. But here we are translating Greek, and I think it is important to reflect how the Greeks constructed narrative material.