So, this challenge to EVs is both obfuscation and seems ignorant of a life cycle sustainability analysis. Let's take the latter first.
The comparison is an EV, like a Tesla, with an Internal Combustion Engine (ICE) vehicle. Independent of their fuel sources, both have upstream environmental impacts, from metals, plastics, and whatever else goes into their manufactures. There are differences, because of the different nature of the designs and engineering of the two kinds of vehicles. ICE's have a lot of machined metals, plastics and rubbers, oils and lubricants. EVs are basically big circuit boards, with most of the mass going into the batteries. Metals need to be mined, purified, refined, smelted, shaped, and transported. Electronic circuits are made on assembly lines with pretty controlled material contributions, and not a lot of transport. The ingredients of LiON batteries might, however.
In terms of fuel comparisons, sure, if the objective is zero CO2 and other greenhouse gas emissions, whether or not the lifecycle usage of an EV like a Tesla lowers emissions depends upon where the electricity gets drawn from. On the other hand, the fuels for ICEs are mined and extracted, refined, pumped, and finally burnt. There is no improving the latter.
But an EV operates in an environment which is changing and which, because of lower costs per unit energy from zero Carbon sources, will eventually move more and more to principally zero Carbon sources. (The idea of needing gas peakers to make up for variation is a product of low imagination on the part of utility owners and a refusal to do things substantially different than they do now. They'll lose, for all kinds of reasons. That discussion is beyond the scope of this comment.) ICE vehicles cannot and will never improve here.
So any argument that an EV does not help the environment only has substance if the region where it is used is pursuing a policy avoiding zero Carbon energy sources. That's not the EV's fault. In the long term, people generating electricity using fossil fuels will inevitably go out of business. A 30 year contract was let in Qatar which sold electrical energy for 17 cents per megawatt-hour, using principally solar, backed up by batteries. No fossil fuel generating source can come close to that cost, even if the subsidies on solar are not counted, and the subsidies for fossil fuels -- for which there are many -- are counted.
Solar's going to eat everyone's lunch.
And, then, effectively, running EVs like Tesla's will be almost too cheap to meter, apart from capital costs for build out.