Yes, travel insurance is worth carrying for a trip through Visp, even though the honest reason has as much to do with what happens after the station as with the town itself. Visp is a rail junction in the Valais Alps, the departure point for trains up to Zermatt and buses on to Saas-Fee, and it is that onward alpine leg - skiing, mountaineering, high-altitude hiking - where a routine trip becomes one that genuinely needs cover.
Switzerland has excellent hospital care by any measure, and Visp itself sits within easy reach of it, but that quality comes at real cost, and treatment for visitors without local insurance can add up quickly even for routine cases. Anything serious sustained on the mountains above Visp is typically stabilized locally, if at all possible, before transfer to a larger hospital in Lausanne or Bern, home to Switzerland's major university medical centers. Confirm your policy pays providers directly or reimburses promptly, since the bill, not the quality of care, is the real risk here.
Skiing and mountaineering around Zermatt and Saas-Fee are the genuine draws for most travelers passing through Visp, and both are frequently treated as separate cover in standard policies - off-piste skiing, glacier travel, and mountain rescue in particular. Check that your policy names winter sports and mountain rescue specifically before booking a lift pass or a guided glacier route, since gaps here tend to surface only after an injury.
Winter in the Valais Alps, roughly December through March, brings the conditions that make this cover matter most: avalanche risk on off-piste terrain, and weather that can close mountain roads and delay trains with little warning. Keep any clinic paperwork, mountain rescue or guide incident reports, and receipts for treatment or transport, and check your policy's claims-reporting timeline before you travel rather than after an injury on the slopes above Visp.