Refillable vapes used to be the standard around a decade ago, back when a liter of vape base (without nicotine) cost 30€ at max. Disposable vapes pretty much didn't exist. Now the same liter of vape base (still without nicotine) is a "tobacco product" and costs 400€+ due to taxes thanks to decade-long lobbying efforts by big tobacco, turning refillable vapes into a massive niche product due to single-use vapes costing the same or less, without any of the hassle of mixing your own liquids or having to refill them.