I would personally argue that 20,000 yen is not a low maximum balance for day-to-day purchases like food, because you can recharge so easily.

Before Suica (and a bit concurrently), JNR and later JR issued "orange cards" that included both high value formats and lower value formats. The "high value" cards were 5,000 yen and 10,000 yen respectively, so the new maximum is 2x the previous "high value" orange cards that they abolished.

The real win with e-money is not getting change, in my opinion. Carrying 20,000 yen in cash is easy when it's 2x 10,000 notes, but when it's a mix including coins, it's a pain.