This is so patently absurd that it goes against around a century's worth of knowledge and scientific research. "Spending more time on a task without rest does not get a job done properly" is not only commonly accepted, but it has been put to the test repeatedly in controlled environments and shown to fail, every single time.
The first link is filled with early-mid 20th century resources on this subject. The rest are all from the 80s - 00s because people... stopped studying this. Most of the studies covered the same thing, and it very quickly became an uninteresting problem in the field of Clinical Psychology because the answer was almost unanimously, unequivocally, "yes, this makes people output lower quality work product". It's one of the most settled problems in Psychology that exists in the modern day.
The only people still researching it are non-profits, and their research serves simply as advocacy, because otherwise businesses won't listen that this extremely, absurdly well-known and well-supported fact is true.
https://igda.org/resources-archive/why-crunch-mode-doesnt-wo...
https://www.tandfonline.com/doi/abs/10.1080/0267837890825693...
https://synapse.koreamed.org/articles/1125602
https://www.jstor.org/stable/40967587
Nevertheless, here is something specific to Game Development from 2016: https://www.takethis.org/wp-content/uploads/2016/08/CrunchHu...
Select quotations from papers quoted in that article:
"In a national Australian survey, employee cognition increased for hours worked up to 25 per week. Beyond that, cognitive abilities decreased. By 60-hours of work per week, cognition was lower than people who weren’t working at all (Kajitani, McKenzie, & Sakata, 2016)"
"In a large study of 4 US-based companies, productivity losses related to fatigue were estimated to cost the employers $1,967/employee each year (Rosekind, Gregory, Mallis, Brandt, Seal, & Lerner, 2010)."
"Lost productivity due to presenteeism (being at work while ill) is almost 7.5 times greater than that lost to absenteeism (Employers Health Coalition, 2000, p. 3)."
"In a study of a large, multi-employer, multi-site employee population, health care expenditures for employees with high levels of stress were 46% higher than those for employees who did not have high levels of stress (Goetzel et al., 1998)."
"People identified as workaholics were found to have higher rates of ADHD, OCD, anxiety and depression compared with those who weren’t ranked as being addicted to work (Andreassen, Griffiths, Sinha, Hetland, Pallesen, 2016)."