Nola struggled once he was traded to finish out the season, dropping from a 151 OPS+ with the Mariners to a 96 OPS+ with the Padres. 2021 was a good year, but only 56 games. He was a 90 OPS+ player in 2022 but still managed a 1.9 WAR through 110 games. Then he fell off a cliff in 2023, hitting just .146/.260/.192 through 52 games, and hasn't been in the majors since.
Dan Altavilla went and threw 8.2 innings with the Padres and did well as he posted a 3.12 ERA. He's been hampered by injuries since, only throwing 5 innings since the start of 2021, giving up seven runs throughout that time.
Lastly, for the Padres at least, is Austin Adams. He only threw four innings in 2020 for the Friars, but had a high-usage 2021 with a career high 52.2 innings, and a 3.89 FIP that was better than his 4.10 ERA. He only threw two innings in 2022 for the Padres, and has spent time with the Diamondbacks and Athletics since.
All in all, that's not great for the Padres. A strong season from Nola and one from Adams, but not nearly what they hoped for, and when you total it up, all they got out of it was a combined WAR of 3.4.