The options for this vary, but electricity-to-fuel is one potentially promising alternative, and would address a few problems in one pass. Biofuels are often mentioned, but a rough feasibility analysis shows that this simply doesn't scale given net biomass potential and human appropriate (see "HANNP" and "photosynthetic ceiling").

Liquid hydrocarbons, for all their faults, are a very nearly perfect fuel: liquid at ambient temperatures (as well as above boiling and below freezing), reasonably non-toxic, proven storage stability for 100s of millions of years, utilisable in a tremendous range of power capacities, from a few watts to hundreds of megawats (an span of 8 orders of magnitude), an exceptionally high energy storage density by both volume and weight, readily containable, non-corrosive to a wide range of metals, ceramics, and plastics, combustion without ash, absent global balance characteristics almost entirely benign combustion products (CO2 and H20), and more. There's a reason the world went so bog crazy for them, and why they're the fuel of choice in our primary prime movers: diesel, gasoline, and gas turbine engines.

It's also quite difficult to conceive of alternatives to present fossil-fuel utilisation in specific areas: air travel, most certainly, quite probably large-scale shipping as well. Migrating away from fossil fuels in both areas would almost certainly mean far less, and certainly far more expensive, options for each. Land-based transport, mining, and construction also strongly favour hydrocarbon fuels. Trucks, trains, earth-moving equipment, and many construction vehicles are more easily accomodated with fuel-based movers than electric.

EVs have much higher drivetrain efficiencies and can benefit from regenerative braking, which effectively delivers about 2.5 to 3x the fuel equivalent of battery storage. Many of these benefits still aren't sufficient to address battery-driven trucking or rail. Electrified rail is possible (and common in Europe), but poses challenges at scales, ranges, topography, and business & financial conditions common to the US. That's not "it can't happen", but it's going to take some doing.

I don't doubt that the future of the fossil-fuel fed engines is limited. A very high tax on fossil hydrocarbon sources -- and I'm looking at rates well over $1,000/bbl -- could well, and likely should be part of that (there are externalities to fossil fuels other than CO2 emissions). But I think it's early to be striking down the internal combustion engine itself.