It’s slow for what it costs. This is a consequence of the particular technological compromises Samsung has chosen to make in order to deliver a high capacity SSD that doesn’t cost an arm and a leg (relatively speaking, the 8 TB unit costs 800+ Euros).
While these compromises may make sense for the larger sizes in the range, 2 TB is a common capacity point now, and there are options that perform better at basically the same price point.
YMMV, though, as different countries may experience different pricing.
The 1080 pulls less than 200W in burn tests, and less in regular use, so there shouldn’t be any problem with your current PSU.