It's one of many ways. And that chart doesn't say they're getting 2x the benefits. It's based off percentage of a household.
There are an estimated 26 million naturalized US Citizens, 26 million non citizens per this report
Which doing some pencil math, us population estimate is 340 million. So even rounding up immigration heavily let's say there's about 280 million natural born US citizens vs. 60 million non-natural born citizens and non-citizens.
At an average household size of 3.2 people there's about 87.5 million natural citizen households, vs. 18.75 million foreign born households. Which would mean that about 10 million foreign born household get a form of welfare (which they consider EITC a welfare for this) while about 27 million natural born citizen households get some form of welfare.
May I suggest reading
This analysis shows immigrant households are significantly more likely to receive benefits.
cis.org
Why Is Illegal Immigrant Welfare Use So High? The high use of welfare by illegal immigrant-headed households may seem implausible. However, there are several things to consider: First, more than half of all illegal immigrant households have one or more U.S.-born children.
15 Second, many states offer Medicaid directly to illegal immigrants. For example, a dozen
states offer Medicaid to all low-income children regardless of immigration status and even more states provide it to all low-income
pregnant women, again without regard to legal status. A few states go beyond this and offer Medicaid to other adult illegal immigrants.
16 Third, illegal immigrant children have the
same eligibility as citizens for free subsidized school lunch/breakfast and WIC under federal law. Fourth, six states also offer SNAP benefits to illegal immigrants under limited circumstances.
17 Fifth, several million illegal immigrants have work authorization, which provides a Social Security number and with it EITC eligibility. This includes those with DACA, TPS, many applicants for asylum, and those granted suspension of deportation and withholding of removal.
18 Sixth, prior research indicates that the overwhelming majority of illegal immigrants have no education beyond high school and, as a result, a very large share of illegal immigrants have incomes low enough to qualify for welfare.19 Finally, it should be remembered that the job of the those in the welfare bureaucracy is to help low-income residents receive the welfare for which they are eligible.