The base model Tesla Roadster is $200,000 and the Dodge Demon is $85,000 to a little over $86,000 depending on where you get the prices. So the Tesla is about 2 2/3 the price of the Demon. I can't afford either one but the people who can afford the fastest aren't likely to settle for second best.
The following list is a breakdown of how Dodge engineers reduced the curb weight of the 2018 Demon.
Removed front passenger seat and passenger seatbelt.
Removed rear bench seat, seatbelts, restraints, and front and rear floor mats.
Removed 16 Harman Kardon audio speakers, factory subwoofer, amplifier, and all electrical wiring.
Removed rear trunk deck lid cover trim, trunk carpeting, and spare tire cover.
Used smaller, hollower front and rear sway bars.
Removed mastic, body deadeners, insulators, and foam.
Used lightweight, all-aluminum four-piston front and rear brake calipers and 360 mm (14 in) front and rear two-piece brake rotors.
Installed lightweight aluminum front and rear alloy wheels and open-ended front and rear wheel lug nuts.
Replaced power-tilting and telescoping steering column with manually-tilting and telescoping steering column.
Removed front and rear ParkSense parking sensors and ParkSense front and rear park sensor module.
I personally wouldn't want a noisy, one seat car with no stereo system, that needs 100+ octane racing fuel that's impossible to find in some places. I live in a fairly large city of over 100,000 people and would have to leave the city to find a Sunoco that sells racing fuel. The good news would be that when I drive north a couple of hours on vacation I could get it there if I needed it. But a car that I could drive around town with a few friends in it, listening to my music that I never leave home without, sounds better to me. But like I said I can't afford either one so it doesn't matter.