Many if not most cordless vacuums at this point have removable batteries, the bigger concern would be whether the company is still making the same style of battery when it eventually dies. A lot of power tool companies are now making vacuums that use their existing lineup of batteries pretty much guaranteeing that there will be spare batteries to be had for years. The downside is that power tool companies are typically not as good as vacuum companies at making vacuums, but there are some decent offerings out there.

Overall I think you get a way better value in terms of performance and cost with corded vacuums and especially tools, but for many people (myself included) the convenience of cordless tools makes it way easier to get chores done. My corded leaf blower is a much better tool than my cordless one, but I blow the leaves off my deck much more regularly now because there's no setup time with the cordless