Earlier quoted context omitted.
Google Apps aren't gold standard. I own a Samsung phone I have replaced launcher (MS launcher) /SMS (SMS organizer). Contacts and Phone app maybe Samsung's but they never troubled me. Only Settings search is unexplicably slow which annoys sometimes. In terms of hardware/updates Samsung is good enough. Only Chinese phones may give better value for money but they come with too many software quirks, which I don't like.
Years ago I used to use the MS Launcher, however I noticed strange behaviour when in low 2g signal areas...Apps would take longer starting up. I'd tap on an icon, nothing would happen and the launcher would appear frozen, few seconds later the app would open. I noticed the launcher was sending traffic whenever I started an app and it was affecting app start times when in low and slow signal areas. I didn't dig in to…
So your experience definitely doesn't come as a surprise.