Well no, I won't.
Because we, too, are a family (on a low income). We, too, have luggage. We pack light (ironically, as of course there is a near unlimited luggage allowance on trains). Even at 7 DS2 carried his own rucksack.
This year we got from Truro to Cologne in one day (could have got to Berlin, but it would have been a pretty late arrival with DC- something that happens all the time with cheap flights, mind you 🙄).
Had a train been delayed? From Cornwall- well, on our very first Interrail trip, our very first train was cancelled! Luckily I'd built in enough of a margin of error that we still managed to catch our Eurostar. If not, we would have had to catch the evening Eurostar to Brussels- they will rebook you without a fuss if you've had a genuine connecting train delay. This year, if our Eurostar to Brussels had been running late, we'd have missed our connection to Cologne- but we would have been able to get the next train an hour later. You see, trains between major destinations go very very regularly. Unlike planes- especially from regional airports- where you often only have one flight a day or less, so if you miss it you're absolutely fucked.
In addition, if a train is delayed you get Delay Repay. Starting at 15 minutes late in the UK, 60 minutes in the EU/ Interrailing. What do you get if your flight is delayed for 60 minutes ? 😆😆😆 I'll have to ask my friends who spent ALL NIGHT at Gatwick with their DC on the way to America last year. I think it was a small bottle of water and a pastry each! Deutsche Bahn would have put them up in a hotel!