For myself, I started off in vector art with Macromedia Freehand and Aldus Pagemaker... then switched to Adobe Illustrator, and some Inkscape... those two were my workhorses for a looong time. I developed a huge library of Illustrator assets over fifteen years of graphic design, technical illustration and architectural illustration. More recently, a couple years back, I moved to Affinity Designer, and despite having to accept the loss of many of my amassed Illustrator assets, it's been overall a fairly painless transition.
Inkscape is free, reasonably effective and powerful, and has the potentially amazing differentiator that it's natively writing
.svg from the get-go, so if your final publishing target is online vectors or logos, it's already there. Workflows are somewhat idiosyncratic, but not unfathomably so; a bit like Blender pre 2.8.
Illustrator is immensely over-featured (just short of Microsoft or Autodesk level bloatware, but just short enough to still be an amazing and effective tool) and a tad expensive for most folks, but can do so much that it's still worth it for a lot of people. Decent range of file exports, slice and export en masse tools are also decent.
Affinity Designer is cheap, the license is perpetual including upgrades, and it's fast. On larger, vector-heavy illustrations, it's noticeably a ton faster than Illustrator. That said, there are quite a few tools Illustrator has which Affinity does not - if your workflow has become dependent upon those, switching can be a royal pain. For myself, I've not found I missed the Illustrator "3D Extrude and Bevel" tools a ton, but that's because although I'm proficient with them, I seldom really use them - if I need a "3D look" I either manually illustrate it that way in Designer (or Illustrator) or I switch to a real 3D DCC tool (Digital Content Creation) like Modo or Blender. Oh and the slice and export toolset (there's an entire "Export Persona") are phenomenal - best in class from my perspective.
As has been pointed out, although the workflow specifics (hit This Button now, then hold cntrl + Esc + / whilst left-clicking repeatedly) will not as a whole transfer from Inkscape to other vector apps (or in fact between many vector apps) the way of thinking you engender when you learn to design in vectors is instantly transferrable, and is the most critical thing to learn no matter which app you choose to use!
Hope this helps.