US Treasuries are considered the safest types of bonds (confining our discussion only to the US bond market). They are backed by the full taxation power of the US government and so are extraordinarily unlikely to default.

In that sense, they set the "risk-free rate of return" by which other investments are baselined. Not happy with the 2.5% (or whatever) on a Treasury? Well, you might want to invest in a state/municipal bond, or a company's bond offering, mortgage-backed-securities, or stocks. You would only invest in those riskier investments if they promised to pay you a rate higher than the "risk-free" rate of Treasuries.

In that regard, rising Treasury rates increase the market-clearing interest rates on any borrowing which is considered riskier than the US government's likelihood of non-payment, so in short, on all other sorts of borrowing. (On fringes, this may not be the case where statutory limits apply, such as on credit-card default rates. If the risk-free rate rises high enough though, such lending might be curtailed in favor of simply moving down the risk ladder if the returns become artificially compressed.)