That is NOT the conclusion of Kleinherenbrink et al. Their conclusion is that uncertainties in the satellite data prevent the acceleration they do see from being statistically significant.
As a consequence, it is likely that a climate-driven acceleration is present in the altimetry-derived GMSL time series, but it is not certain.Note that the inability to state that an acceleration is present with certainty using satellite radar altimetry does not imply there is no acceleration at all. Its estimated value in this study is actually in line with the results of the 20th-century tide-gauge-based GMSL reconstruction by Dangendorf et al.17, notably 0.018 ± 0.016 mm yr−2. The uncertainties in the altimetry-derived estimate, however, cause the same acceleration to become statistically equivalent to zero at a 95%-confidence level.
Yes, humans are increasing coastal landmass faster than the rising sea is taking land away. However, all this new land is low-lying and subject to increasing flooding as sea levels rise. You failed to include the following observation from your linked article:
“About 70% of coastal land expansion has been carried out in low-lying regions that are likely to be exposed to extreme sea level rise by the end of the century. Both environmental impacts and projected coastal inundation suggest these developed coastlines are not sustainable, but cities will likely continue to build them, the authors said.”
They will certainly face a future where most of coastal FL will be subject to frequent flooding. Insurance for buildings will be very expensive or unavailable. The unavailability of insurance will mean that sustainable habitation along the FL coast will be increasingly not economically viable.