Ikea used to make a stool called the Bekvam which is perfect for younger toddlers to be able to reach the sink in bathrooms. Its more space efficient too vs regular learning towers.

Unfortunately, they no longer make it. You can still buy it on amazon though - https://www.amazon.com/BEKVAM-Home-Indoor-Solidwood-Stool/dp/B002EGZF8A?th=1. Ikea used to sell them for $20, so paying $40 seems kind of ridiculous.

I did pay the $40 last year though, right around when my daughter turned a year old, and she still uses it. She's about to turn 2 and would definitely still need this type of stool to reach our bathroom sinks. And she's tall for her age!