Flash memory is mostly being sold with capacity as the selling factor, with perhaps reading speed as the other selling factor. This means that most manufacturers don't care about writing speed, and are happy to use components with large capacity and good reading speed but poor writing speed.
In the days of 2 GB Flash memory cards, SLC technology was being used which has better writing performance than the MLC technology mostly used today, while MLC technology is cheaper per MegaByte.
If you want better write performance, you need to seek out Flash memory cards that actually advertise a high writing speed, such as e.g. the SanDisk Ultra and Extreme cards.
Welcome to the MyCE forums!